I don't think you will find new shoes on someone's retail shelf. Take your old shoes, along with the drums and go to TruckPro in Phoenix. They used to be known as Phoenix Brake and Clutch. They will media blast your shoes, paint and reline them. Then they can turn your drums, if there is enough metal to do safely. Have them arc the shoes to the drums so you don't have to wear them in to function correctly. Kent
Even for my 1959 2.5 ton I was only able to find off-the-shelf wheel cylinders for my truck. I took the drums to a machine shop to get them turned and re-used the old pads.
Your best option is to find a service that can re-line the brake shoes, or learn how to do it yourself. Unfortunately with this age and size of truck, you are at the limit of what can just be part-swapped.
Newbie here, just rebuilt front brakes and new kingpins on my 1949 Chevy 4400 1 1/2 ton grain truck. I purchased relined shoes from Jim Carter after sending in my cores. Very satisfied with parts and have good front brakes with hydrovac system and new single brake master. My rear brake line was blocked off when I bought the truck, so the rear brakes will be my next hurdle.
That looks great Spark, nice work. I'm debating on whether or not to clean up and paint my front drums. I did the rims and now the rusted drums stick out like a sore thumb.