eclector - You probably already know that the front drums GM# 609779 for your 3/4 ton are listed in the Master Parts Books as a 1 year only. The rear drums are listed as GM# 609807 and were shown fitting 1946-52 3/4 tons.
Both have achieved "unobtanium" status as far as I can tell searching through the web. The only listing I found was for the rear drums at Jim Carter under
MEB126, but they have been out of stock for a long time and unlikely to come back in stock. Absolutely no front drums listed anywhere, not even used stuff.
About the only thing I can offer is to suggest you search your local FBM and Craigslist ads for someone selling off axle assemblies or parting trucks that might still have something useful on them. Other than that, reach out to fellow 'Bolter KCMongo as he might have something used still on hand.
NOTE: I've moved your post to the best forum to continue the parts hunt conversation.
