one of my brushes was actually cracked and chipped around the edge, which incidentally is also the one with the broken lead. There was caulk in there from before, however.
I hadn’t thought about the armature but the lead/copper brushes aren’t going to be much harder than the carbon copper ones in there already. The only downside I can think of is that the current ones are a bit self-lubricating whereas the copper and lead mix will not be.
