JMHO....I agree that this would never be a commercial venture... The market is just too small with how manufacturing works today.. There will be those who try, but they most likely will always be in the over $100,000 range...
To me, it's of dubious value anyway. My whole mentality of car ownership and modification is applying modern/high end materials (titanium/carbon fiber isn't technically 'modern', they've been around for quite some time) to older cars. I realize though that I am not the most impartial candidate as I am of the opinion that there haven't been any real improvements to the automobile since the '70s... A modern engine? Computer controlled, miles of vacuum tubing going who knows where, doing who knows what? A plastic cover hiding most of the engine? Need to plug it into a computer just to find out that the Pfetzer valve is 'out of range'? No thank you.. If my car won't start, it's one of 3 things. Gas, air, or spark. I'd take an oversquare, Lampredi SOHC with carbs over that any day... Plus, all the use of plastic parts that should be metal in modern cars is INCREDIBLY frustrating.. This is cost cutting, not weight saving as BMW would have you believe.. I think I've replaced the clutch pedal twice in my wife's Z3 M Coupe.. The next time it fails I'm fabricating an aluminum one.. I've already replaced most of the cooling system with metal replacements, as well as the master cylinders... Master Cylinders in Plastic??! Really? That car's 20 years old, it's only worse now... If all these 'modern' materials where supposed to cut weight, why is every new car well over 3000 pounds? Even a new 'Mini'...
Anti lock brakes? That's your right foot. Traction control? Buy good tires and learn how to drive properly... Power steering is unnecessary if your car is under a ton, and only serves to numb the driving experience... All of these 'improvements' are making this new generation some of the worst drivers on the road. If you can't parallel park a car on your own, you've got no business driving a car, get an Uber.. There's a girl at work, 24ish, whose brand new car was in the shop so they gave her a loaner that was just a few years older. Both cars automatic, but her's doesn't require you to hold the brake at a stop light. It stays stopped until you press the accelerator. Her loaner of course did not have this feature. She of course rear ended somebody 4 miles from the dealership.. She wanders in and out of her lane because the car doesn't warn her she is doing it. They don't treat driving like something they need to pay attention to, I've never been more terrified/horrified on a 2 mile drive to lunch... I can't count how many modern cars I see driving down the road at night with the lights off.. Used to be easy to tell, if the dash lights weren't on, your lights weren't on... That's not the case anymore.
What was wrong with an accelerator cable? That item rarely needs any service, but how many of those 'drive by wire' cars drove away from their owners causing accidents? You know that's not a performance enhancement, it's to make manufacturing 3 cents per car cheaper, and no longer owner serviceable...
My biggest beef with older cars are things like interiors fogging up or leaking in the rain, or the strange way Fiat wired their cars so that most accessories only see 10 volts.. But those problems can be fairly easily solved. What are you left with then? A cool, fun to drive car that doesn't look like it's had cheese melted over it and isn't hard to tell if it's a different car than the one next to it at a stop light...
I'd be ALL for a carbon fiber bodied X19 with titanium suspension arms, 6 piston brakes and carbon rotors that I can stuff under 13", negative offset wheels and a 2 litre Fiat Lampredi SOHC with a bank of 4 flatslide carbs. But no company is going to build that and sell it to you for 40 grand.....