Daren,
I have welded new rims on the pressed steel brake drums (1925-1930ish), using the original backs. Use 8" heavy wall tube, then turn true in a lathe after welding. Of course to do this repair one needs a decent back/center of an original drum to start with. One can leave the outer diameter a little larger than original to add some much needed stiffness.
The later cast iron drums (starting in 1930 on some models till 1938) are in short supply and there is usually someone at any given time desperately seeking the same. Eventually someone is going to have to take on the project and have them re-cast.
-Doug
