Do you have any pics to show?
It's difficult to prepare a budget without a full inspection.
There will be probably some corrosion.
I'm one of those who think that the only way to make this things is go for a completely restoration.
Dismatle the car, repare rusty and corrosion damaged areas, full body restore, new paintjob, new carpet, upholstery, engine and gearbox rebuild, and use NOS parts to achieve the original look.
If you'd spend your money in not making a full restoration, but improving all the wear parts, and the things more important to do, you'll be finally wasting the money twice and remake it from zero.
It's better to make it once and make it with a high exigency level.
Nevertheless, this a single business in this operation = money
I don't know what you think to spend, but when you're in the beginning of a restoration, the problems come to you from heaven. All the initial budgets became to duplicate at the end of the work.
Look at this: