This Local Machinist Makes Custom Parts for Some of the Most Expensive Cars in the World

Collectors from around the world seek out Jim Simpson when an old, discontinued part breaks down on their Ferrari, Lamborghini or vintage Rolls-Royce.


You’d think that a guy who works on Ferraris and Lamborghinis would occasionally get to take one out on the road for a test drive. But Jim Simpson rarely even sees such fancy cars or their owners.

Instead, he’s the last resort—the fixer, the old-world machinist, the Geppetto of exotic cars—the one collectors from around the world seek out when an old, discontinued part breaks down on their vintage Rolls-Royce or Duesenberg or Avions Voisin.

In an age of mass production, Simpson makes precious one-offs. Most of the time, he’ll receive the broken part in the mail. Other times, he works from blueprints, photos, and sketches.

His job is to replicate that lost piece, often making it better than the original.

“We’re putting braces on the ‘Mona Lisa,’” he says, standing in the middle of a shop filled with so many gadgets—turn signals, wheel covers, lock cylinders, horn buttons—it’s hard to know where to look.

A gearhead’s museum of lost treasures

Working out of a refurbished chicken coop west of Sonoma, Simpson named his business O.D.D. Parts Fabrication as a tribute to all that is Obsolete, Discontinued, and Difficult-to-Obtain in the automotive world.

His shop and warehouse is an amazingly well-organized gearhead’s museum of lost treasures.

There’s a pedal-powered lathe he converted to run on electricity. An electroplating operation, hooked up to a car battery, that involves melting down pennies for zinc. And a wheel to spin and shine new wheel covers.

His trusty team is hard at work. In one corner, Steve Clark is busy building Ferrari license plate holders. Across from him, Matt Loftus is making a diaphragm for a carburetor in a Jaguar XJ6.

Nothing is thrown away, nothing is wasted at the Sonoma warehouse of custom machinist Jim Simpson. Racks of drawers contain small parts and samples. (Erik Castro/For Sonoma Magazine)
Nothing is thrown away, nothing is wasted at the Sonoma warehouse of custom machinist Jim Simpson. Racks of drawers contain small parts and samples. (Erik Castro/For Sonoma Magazine)
Jim Simpson of O.D.D. Parts Repair & Fabrication working with his two employees Steve Clark, 79 and Matt Loftus in his workshop in Sonoma, Calif. on Oct. 30, 2023. (Photo: Erik Castro/for Sonoma Magazine)
Jim Simpson of O.D.D. Parts Repair & Fabrication in his workshop in Sonoma (Erik Castro/For Sonoma Magazine)

When a new customer walks in to pick up a metal rod he ordered, his eyes light up, seeing the shop for the first time. “It’s kind of a candy store,” Simpson says, midway through explaining how he can bend, cut, fuse, and bevel glass, and cast both metal alloys and plastic.

“If you’re looking for a weird item, keep us in mind,” Simpson tells the customer. It could be the company motto.

Later, a machinist with a thick Ukrainian accent calls to talk through pricing for a 1936 Rolls-Royce restoration project. Good-natured and quick to laugh through a bushy moustache, the polymath Simpson hardly ever stops talking, going on about almost anything—politics, 3D printers, Russian vloggers, Italian shoes, steampunk style, recumbent bikes.

In the niche world of elite vintage car restoration, Simpson has earned the reputation as a maker of missing puzzle pieces. “He makes what they call the ‘unobtainium’ parts—the stuff you can’t find anymore,” explains one client.

From fine arts to fine cars

Simpson likes to say he was born “when a pickle was a penny.” Growing up in Orange County in the 1960s, his family garage was the neighborhood hangout. It’s where Simpson built tricked-out soap-box cars and later a fiberglass Devin kit car. A hippie with hair down to the middle of his back, he rode the rails across the country and into Canada and Mexico as a teenager.

A few years later, after earning a fine arts degree, his first job was repairing washing machines and refrigerators at an appliance store. Migrating north to the Bay Area, Simpson worked at several car parts shops, before eventually going into business on his own in 1990.

Today, at 73, he’s still an old hippie at heart. He worked out of his home garage until about eight years ago, when his wife busted him for carrying a cauldron of molten aluminum through the kitchen.

Simpson’s workshop contains all manner of rare and rehabilitated machinery, from metal lathes and die-casting equipment to circuit boards and small electronics—all remarkably well organized. (Erik Castro/For Sonoma Magazine)
Simpson’s workshop contains all manner of rare and rehabilitated machinery, from metal lathes and die-casting equipment to circuit boards and small electronics—all remarkably well organized. (Erik Castro/For Sonoma Magazine)

The maker of missing puzzle pieces

For Simpson, it’s all about the chase and the thrill of solving a puzzle. Along the way, he wants to make the client happy and make a buck at the same time. But ask him if he’s a good businessman and he shakes his head.

“I’m way too friendly,” he says. “Nice guys finish last.”

Hearing this, Loftus leans his head into the room to add, “You’re a very good salesman, but not necessarily a good businessman.”

Simpson can’t help but agree. “We never have anybody complain about price, so we must be doing something wrong.”

But word of mouth among super-wealthy rare car collectors keeps him in business. In the niche world of elite, vintage car restoration, Simpson has earned a reputation as the maker of missing puzzle pieces— a tricky endeavor when said puzzle company probably went out of business 75 or 100 years ago.

“He makes what they call the ‘unobtainium’ parts, the stuff you can’t find anymore,” says Elliot Siegel, a retired Chicago commercial real estate developer who hired Simpson to replicate parts for two Maseratis and an Alfa Romeo. “Sometimes people will send him drawings, and he has to create something from scratch. He’s an Old World craftsman. Instead of making fine jewelry, he’s making parts for vintage cars.”

Jim Simpson of O.D.D. Parts Repair & Fabrication working with his two employees Steve Clark, 79 and Matt Loftus in his workshop in Sonoma, Calif. on Oct. 30, 2023. (Photo: Erik Castro/for Sonoma Magazine)
All manner of tools are organized in Jim Simpson’s workshop in Sonoma. (Erik Castro/For Sonoma Magazine)
Jim Simpson of O.D.D. Parts Repair & Fabrication working with his two employees Steve Clark, 79 and Matt Loftus in his workshop in Sonoma, Calif. on Oct. 30, 2023. (Photo: Erik Castro/for Sonoma Magazine)
Colleague Steve Clark has been a tinkerer all his life. (Erik Castro/For Sonoma Magazine)

An award-winning automobile 

Reno collector Steve Hamilton, who owns more than 80 exotic cars, including Rolls-Royces, Ferraris, Lamborghinis, Aston Martins, Duesenbergs, and Delahayes, first hired Simpson to restore a Ferrari 400i electric side mirror that no one else could fix.

When it came back in perfect working condition, he challenged Simpson with an almost trivial pursuit—replicating a matching tortoise-shell-covered perfume bottle that was included among the vanities in the backseat of a hand-cranked 1907 Renault.

Back then, cars came with vanity collections, like you might see in a limousine, including ashtrays, clocks, and in this case, left and right perfume bottles for the ladies. Missing one bottle, Hamilton sent Simpson the original for reference.

“To tell you the truth, when he sent them back, you could not tell the original from the replica,” says Hamilton.

In 2021, the 1907 Renault with the now-perfect perfume bottles won first place in the preservation category at the annual Pebble Beach Concours d’Elegance, widely considered one of the most prestigious car shows anywhere. “There’s nobody else who could have done what he did,” says Hamilton— before rattling off the next round of cars he plans to bring into Simpson’s world.

O.D.D. Parts Fabrication. 707-738-9661, oddparts.net