In the never ending quest to isolate a vibration in my '55 CDV, the question came up, is it possible to check and if necessary, rebalance the brake drums?
In a word, Yes.
I have seen many brake drubs with Balance Weights attached to the steel portion of the mounting flange which is bade of steel.
Brake drums come balanced from the factory and have weights welded to the outside of the drum. The simplest way to balance a tire and brake drum is to spin the tire on the axle and there are machines that tell you where to apply the weights to the rim. This way your brake drum rim and tire are perfectly balanced
might be easier to get a good one and swop it out, one by one, til you find the one that's causing the issue. Make sure the tire and rim is spin balanced first. If they were cut properly, should not be out of round. It's possible to cut them out of round if not mounted correctly. But the remaining thickness should be obvious to cause problems. Plus it should shudder more during braking than just rolling.
How's the spindles? Are they worn down were the bearing races sit? May need to be filled and cut back.
Some of these early rims are riveted, and can corrode or come loose in the gap and cause issues.
Maybe some other wear suspension issues that are contributing to make a small issue large.
I had a vibration in my 1955CDV and struggled to find it! My issue turned out to be my motor mounts! I ended up having to ream the engine block mounting holes (for the mounts) oversize for bigger bolts. (the block holes were wallowed out) Problem solved!....walt...tulsa,ok