Those are Huck brakes. Pre-Bendix. harder to find parts, but work well. NOT self adjusting, and both ends of the wheel cylinder need to be adjusted regularly. I had my 3/4T shoes relined at a truck shop. They did good work. Just my opinion, but a dual cylinder master is a good idea. I got a mounting kit from a local shop and a drum-drum master for a 72 3/4t from NAPA. All new lines. Works great, and peace of mind.
If you need to do bearing work, you will need the proper socket for the hub. Look at the internal ring nut after you pull the axle shaft so you know how many teeth you need on your socket. If you find one, buy it! It's a good $20-30 investment which will save you time searching when you need it. I believe mine was marked for 67-72 3/4T 4wd, but it fits and works. Your axle should be the same HO52.
It would be nice to find a newer truck that had brake drums similar enough to use, but no luck yet.

Good luck and enjoy your truck.

Current fleet (subject to change w/o notice)
\'49 GMC 3/4-Ton , 60 Austin Healey Frog-eye Sprite (some assembly required), 2011 Dodge Avenger, 2015 Jeep Cherokee. No, they don't all run.
My other ride is a (B737)no, (B767)no, A320.... Update... was Embraer E190, now Boeing B787.

Knowledge is a wonderful thing, but ignorance means you don't know you can't do something.