I have had the same issue with my '03 Speedmaster. I have just peeled off the loose stuff and left the bare metal. No rust so far. I keep meaning to do something about it but I have no idea what to do. Whenever I stop into Manayunk Triumph I keep forgetting to ask about that. Stop there and talk to Buzz or Tommy, they'll know what to do. If I think of it, I'll give them a call.