The only advantage of a 75 or earlier car in California is that its smog exempt.
Otherwise I would buy a 1984 Carrera for around the same price.
The late model interior, etc. and galvanised parts would make the 1984 a much better buy.
If I was going to go cheap I would look for a good SC.
I also don't understand that baby on the way crap.
I bought a 993 because it has a back seat for the kids.
I take my 3 kids to and from School in my 993 all the time.
As far as I know all air cooled 911's have a back seat unless they went with the rear seat delete option.