These are all difficult questions to answer. And in most
cases can not be answered even with the car on the lift. The reason is, a car
that's 30 - 75 years-old has many hidden problems. Finding them usually happens
after disassembly.
Every car is different, what takes an hour to repair on one,
takes 3 hours on the next. Parts for one are available everywhere, others
require a more in depth search. Some parts go on like a glove, other require a
slight finesse, and still other require a big hammer (well Rubber mallet, ha-ha)
- [more work].
So basically every car is different, even 2 1957 Chevy
Bel-air's have seen different lives and need different attention.