Jasper, you have asked a very open-ended question, kind of like "I see
an old house, should I restore it, and how much will it cost?" You
won't know any answers unless you a) have a survey done of the boat or
b) know enough to do it yourself.

That being said, lots of people with more time and money than brains, I
mean, with lots of ambition, have taken on seemingly hopeless projects
and with persistence and cleverness have wound up with fine vessels,
all the better for having restored the boats themselves. I say, go for
it!

As for the USS Constitution, if I recall correctly there is but one
piece of original wood in her, and it isn't structural.