Chess piece restoration question

I‘m restoring a set of chess pieces that I believe are around 50 to 60 years old. The weights on some of the pieces have a rather thick layer of oxidation (see photo). Some of the pieces have no such oxidation. I’ve started removing the oxidized material with a hand file (yes, I’m wearing a mask since I suspect the weights might be lead). My question is whether any of you can recommend what to coat the weights with to reduce the rate of oxidation after I remove what’s already there and before I apply the felt.

Thanks in advance.

Think the issue may be a glue problem rather than an oxidation problem. (?) In these cases I pry out the weight , clean out the hardened glue, and then reset the weight, which usually fits perfectly once the excess glue is gone. That way you don't get rid of weight from the piece. Can be hard to remove the weight though and it may need to be reformed with heat. Alan Dewey has some videos on how to do this. Sanding will work too if you don't want to do a major job. Don't think it needs any treatment after being remounted flush.

If it is excess glue that might help explain why only about a third of the pieces have the issue. I've only worked on four pieces so far and found that once I get the surface of the weight smooth a small portion of the metal is still protruding from the wood base. I feel safer filing the excess metal down rather than trying to pop the weights out and reset them. There seems to be enough of the weight left after filing it to leave the pieces with enough heft for me.