Given one of the cars Abacus is saddled with is my fault, I'm chiming in.
What I see in this thread is some legit concern over how one can can keep ageing vehicles on the road reliably.
However, I'm reminded of a good friend and former coworker who immigrated from Cuba.
For a long time, they had nothing, but nothing they could get parts for. Nothing got through the embargo.
They still kept everything on the road.
55 belair engine worn to the point it will not take a 6th rebuild with thrice-knurled pistons? no problem - we'll make a Lada engine from the 70's fit.
No more gasoline? no issues - we'll create a pre-heat box to melt lard and then atomize it in another hot-box before feeding into a modified carburetor.
These guys could keep anything on the road - they saw a broken part as a challenge, not a dead-end on an older vehicle.
They
ran turn-of-century steam locomotives until recently because they kept making any of the parts which broke or wore out, and because the couldn't buy anything new.
C'mon - certainly we have the know how and the resources on this great continent to be able to come up with solutions to the challenges posed above re NLA parts and other ageing car related issues?