There is a repair for badly worn brake drums I have seen on quite a lot of old cars over here.
The brake drum is machined out in a lathe, then the brake drum is heated and shrunk onto a steel band (basically a short section of large diameter seamless tube) and turned on a lathe again to ensure the correct internal diameter and concentricity.
You need to have this modification done on both drums on an axle because the friction generated of the brake linings is different against steel and cast iron. I spent a long time trying to cure a brake pull on an old Austin car before I spotted that a PO had only had one front drum repaired with a steel sleeve.
