Having my '81 280ZX being repaired at the moment I would suggest budgeting for more time and money than what you want to spend. Certain parts can rust easily, one bad spot that I had found was behind the rear bumper, the join there was very bad. Another weird spot to check is under the sound deadening, if it has blistered or bubbled at all, check under it cos I found several holes under there.
Don't be detered by any of this, what you have is an amazing car and will be worth every cent and every drip of sweat. Let us know how it turns out
