WHen the cab off is the easiest time to get your brakes in good shape. As Chev4t6 said, rebuild/replace master and wheel cylinders, brake lines, shoes, drums, springs, hold-down pins, etc. The brakes should definitely be in top notch condition! I've kept the original front end and brakes, kept them in good condition over the years and they've always worked great. The brakes and steering are different than a modern car, but kept in good shape, it by no means is bad or unsafe - after all, it's a truack and an old one.
Samantha