My first inclination is to ask ..Why?... but I get some strange ideas running through my head frequently as well. First, the conversion cylinder chambers probably have a restricting "throat" that would be problematic since it's measured for a 45lC round vs. a 45 casull. Probably won't chamber a casull. Probably have the same issue with a regular .410 round. Say you ream out the chamber throats, you'll mess up any accuracy for 45LC rounds, and .410's will have a bad donut pattern anyway because of the barrel rifling. You can always load 45lc brass with BP and shot. I've done that, and it works ok as a close up snake load, but that close I could probably hit it with a bullet anyway.
Adding: With a cylinder as long as one for a Walker, you could probably ream the throats to take casull brass, and get a bit more powder in there. I would imagine that could hold nearly 50gr fffg with a little compression. Not sure the conversion cylinder would be safe with that or not. And if you ever put a real 45 Casull round in there, you'd have a pretty nice grenade.