Ive got a 1947 Advanced design GMC 300

Are brake parts even still available for big trucks like this? I haven't taken the drum off to inspect but I can only assume the pads need replaced. The truck has been sitting since the 70's.
If they are savable thats great but just in case does anyone have leads on parts for these bigger trucks?

its frustrating that all the 1/2 and 3/4 ton trucks have brand new parts available but were left out to dry.


Logan
2010 Silverado 2500HD
1947 GMC 300