Ibdot;
I have to agree with the sausage king. :-)
You have a beautiful truck. It looks like it is all there and in pretty good shape. I would get the engine running and tuned up and get it on the road. Once you drive it a while you will get a better feel for what you want to do. Don't be fooled by all the lemmings out there. Bigger and newer isn't necessarily better. As many people will tell you, a good running stovebolt is plenty enough for these old trucks.
I faced a similar dilemma when I picked up my 58 Suburban. It was completely there and all original accept for a 250 in place of the 235 and clamshell doors in place of the original barn doors. It is almost rust free and rock solid for its age. I felt like it would be disrespectful to hack up such a pristine example of classic Chevy iron. If you were forced to pick up a previously done truck or someone's stalled project that already had a bunch of mods, that would be a different story. I personally think it is our duty to preserve such high quality examples of old trucks as much as possible. There are very few examples of unmolested Stovebolts left out there. We need to keep the history alive.
All that being said, my motto is "safety first." I have no issue with some modern upgrades in the name of making your vehicle safer. Maybe that makes me hypocritical, but a good quality breaking system is an authorized modification any day of the week in my book. It's not that the breaks are poorly designed. They were fine for the circumstances of their day. Now you have to content with distracted idiots that will dart out in front of you and slam on the breaks in their 2200 pound import that stops on a dime. It takes a lot longer to bring a 4000 pound 70 year old truck to a stop. It all comes down to how you want to use your truck. If it will be an occasional trip to the ice cream store with the grandkids kind of ride, the original breaks, in good working order, would be fine. If you want to make it a daily driver and get it out on the road I would go with updated breaks. I currently have the original drums on my burb but plan to upgrade to either power assist or discs at some point. I try to be very careful when driving but I've still had a few white knuckle experiences. Kind of goes back to my rule about preserving the old iron. Keeping it out of an accident is part of that preservation.