Let me say this: your truck looks a heck of a lot nice than mine did!
While it is possible--I wouldn't expect your brakes to simply fail out of nowhere, but rather start leaking one cylinder at a time, maybe worn shoes, etc. Just thought I'd let you know to be ready to replace the parts (oh, and don't forget the rear hub seals!).
Sounds like you and your family/friends are MADE to restore old cars, you have a lot of skills that fit well with this hobby, very cool.
I might even PM you with some welding questions, if it's OK with you.