Alas - just checked the bores and they're 28" form the nipples, 27" from the front of the plugs, so unless going to 24", there'd not be much sence in shortening them for weight or balance change.
I did re-crown as they had the typical sharp edges, although they did have a mild chamfer. My normal patch material cut with the factory muzzles, but now shows no damage what-so-ever. The balls are nicely engraved by the lands and the bottom of the grooves - this with a .022" ticking patch and .562" ball. My normal ball diameter for a .58 being .575" with the same patch, I might get away with the smaller ball. Only shooting will tell. The rifling depth isn't great - appears to be about .008" - perhaps a .570" will be corect. Again, shooting will tell. I was happy to find the bores non-pitted (didn't use a magnifyer, though), although I know the gun has been fired with pyrodex. There was mild rust in the bores, typical of 'casual' muzzleloading shooters, I find.

Ron - how do round balls shoot in your cape gun? We've found the .54's to do quite well on moose and elk as long as one stays away from heavy bone - to a longest shot of 170yards. The moose ran flat-out for 40 yards, dropping dead in is tracks - double lunged and heart centred as well. Velocity 1,750fps at the muzzle for that load. The ball was under the hide on the far side after holing a rib on the entrance side - or was it exit side?