It can take a long time to properly restore an old Mustang or ’57 Chevy. The nice thing is that nearly all the parts usually are easily ordered by specialty catalog, and are just as easy to install. Custom cars are tougher. They require things like fabrication, testing, redesigns, fitment checks and a final assembly with fingers crossed.
If your ultimate goal is production, it’s even more fun because every nut, bolt and custom part requires a drawing or a Bill of Material (BOM) to show what’s needed to make that part. You also need CAD files, a vendor list, assembly steps, and dozens of other items that aren’t required even with a custom build. That’s what we’re going through now.
I was reminded of the difference between a restoration and a ground up production build when I looked at The Catfish next to an old Triumph GT6 awaiting restoration. The old car (owned by an ex-Formula One racer) is fairly rare even by collector standards, but replacement parts could easily be found to put it back together quickly. The toughest part would be convincing the family of rats living in the engine to find a different residence. 🙂