I concur with Kevinski on the existing bearings/races. Clean them up, as well as the spindle, inspect them for wear/damage and if none found repack them with good quality grease and reinstall with new seals.
How-to's on all these tasks is as easy as clicking your mouse to find what you need in this free web resource
Chevy Truck Shop Manual which also covers your '52.
Just my $.02 worth, but if your going to replace one wheel cylinder, go ahead and replace them all. Same for brake shoes and flexible hoses. Even though the one functioned when you pushed the brake pedal, it's likely well worn and your better off (safer) replacing them all to ensure functional and even braking. Think "Safety First"!
There are other resources to help you bring back those found memories with your grandfather redoing the brakes.
Here's just one on
Servicing 1951 Chevrolet Car and 1/2 ton Truck Brakes that can really be a help.
