1941 would have been the huck brakes. Not sure if there were any changes in them between your truck and 1950 when they chnged over to Bendix or not. I should think replacement or rebuild kits are available for the wheel cylinders. I believe you are only allowed .004 thousands on honing a wheel cylinder. So if the bores are pitted then you'll need to replace them or have them sleeved.
Anyone had their brake wheel cylinders sleeved with stainless or brass? I believe White Post did them in brass, but did see others offering slainless sleeves.

John