I've never done it so this is hearsay: one post I read recommended drilling out the small pin that holds the arbor. Threading the hole and installing a set screw. If it is still loose (which is likely) then unscrew the arbor. Thouroughly clean the threads in the frame & on the arbor, applying epoxy or JB Weld and screwing the arbor back into the frame. Reassemble the cylinder, barrel, and wedge. I can't remember if you let the epoxy set, then clean the threads off in the hole for the set screw and reinstall the set screw or just repin it and let the glue set. Obviously, I am not a gunsmith or I would have the procedure more clearly stated.
With over 15 perCUSSIN' revolvers, I've been called the Imelda Marcos of cap & ball.
SASS#3302 (Life), SASS Regulator, NRA (Life), DGB#129
Wolverton Mtn. Peacekeepers (WA), former Orygun Cowboy (Ranger, Posse from Hell)