I bolted a lot of pads to brake shoes 50 to 60 years ago. The bolts can still be bought.

https://www.lawsonproducts.com/lawson/Brass-Brake-Shoe-Bolt-38-16/1450A.lp

Later we switched to rivets. Brakes use a hollow shank rivet and we were accustomed to working with rivets anyway. They weren't any better, but they were much quicker.

As for the drums, hold on to them. There is a good chance that you won't be able to find new ones and you will have to turn your old ones.