When my son was 2 I had high expectations and he still surprised me with how relentless he was at fuzzing the iPad. He doesn't understand what any words of symbols mean but he knows how to navigate it. At 3 he can mouse and keyboard his way into youtube and search for "trains" without being able to tell me whay that word means.
I'm so glad he's thriving with a mouse and keyboard. I worried a bit that he was doomed to be a touch screen computer user.
I'd expect the same is true of old cars, and whatever else; even if you're tinkering with things initially out of necessity, if you're determined enough to pull through, the experience may wind up being an investment in and of itself.
Do your job of being our product and make as little fuss as possible.
If you were to throw a relatively cryptic and unabstracted machine in front of a bunch of five year olds, like a Commodore 64, they would probably both eventually figure it out and be better for it.