I think Ian largely answered his own question when he mentioned bicycle spanners. Few today have even that background. A fix it mentality was common. Very evident from the fascinating Popular Mechanics of the time.

There is the crude lash up to get a car mobile for a while and the careful selection and correct assembly of used parts to give a service life comparable new. Quite different situations.

From my experience, for makes which have required professional “mechanics“ unfamiliar with to work on, a chain of compounding trouble is often generated by their efforts. Patient and observant amateurs often do better.

I have been told that dishwashers are a remedy for oily clutches and brakes, but not good for aluminium shoes.

Location: Auckland, NZ

OK, I was a privileged schoolboy, but it seems to me that the biggest differences today are price and availability. Back then, if you got it wrong, you could get an entire replacement engine from the scrappy for 30 bob.

Location: Richmond, Texas

30s for an engine is certainly cheap but when adjusted for the price index (or better typical wages) those old prices were not quite such a bargain. Our money is comparable to UK but old cars were much more expensive. In the 1960s £20 was a very good wage. I paid 10s and £2 for gearboxs, £3 for a good diff assy, £5 for a derelict RP and reasonable but non running Sevens were usually at least £25. The labour to rebore a Seven block was £3.10s, remetal big ends £6. I used to buy smooth motorcycle tyres for 10s each.
A comparable wage today is $1500 or so, but legal satisfactory running late 1990s cars can be had for $1000 down to $500 or less with a little hunting. So cheap that nobody works on them to devlop skills for maintaining Sevens in future!

Location: Auckland, NZ