Hello Crypt0manic. I'm not an expert by any means, but you may try to insert a screw in the lead ball and remove it by pulling on the screw with some plyers?
If you don't know these YT channels, you will find a bunch of great advices and how-to about BP revolvers here :
Mike Beliveau
Blackie Thomas
If you don't know these YT channels, you will find a bunch of great advices and how-to about BP revolvers here :
Mike Beliveau
Blackie Thomas