I had a peek at my spare cylinder yesterday, looks like you can clean up the transfer angle using a drill bit (preferably in a press but a hand drill would probably do it too), then clean it up using a dremel. I prefer not to use JB as last time it melted. You need the case compression to stop the exhaust gases from melting it. Plus I'm not a fan of shrinking the already tiny transfers. I'm not sure how much you can remove just yet, havent done a test drill but I probably could today.
I have a very small dremel extension, the dremel branded one is too fat to get in there, I got one from Sears that's a small pen-like extender that can fit right into the transfer ports