Here in Wisconsin the way I understand it, even if a car never offered seat belts you have to add lap belts at a minimum. Even if a seat wasn't designed for a headrest (American term for them...some car words are different in UK English*) or seatbelts (either kind) they can be added with a bit of enginuity.
I seem to recall reading that Nash cars of the 40s could last better than 150k. When you say grease do you mean wheel bearings or ball joints....cars here in the US don't self grease either of those... though the higher line 58 Lincoln's had a button to push that would automatically grease all the ball joints...there is a neat feature I'm surprised didn't last.
One thing that I miss (aside from floor mount high beam switches you meantioned (and my 78 Lincoln has) is hood ornaments....there were a lot of cool ones down through the years but pedestrian crash safety standards have pretty much killed them in current production cars.
*The Britt's can keep their sissy bonnets, I want an American car with a real hood... though I do gotta give them props for calling their sedans saloons....If they got their UK name the way I think they did there must be a lot of 4 doors there with whiskey dents....
