I may be late to the party, but I just saw one of the SASS gunsmiths (Cody Conagher) is offering a .45 ACP conversion for the 1873 clones.
Kind of interesting but the cost is almost $600. I have no information on the number of rounds it holds.
The .45 LC bore is typically .454 and larger than the ACP, so I am not sure if he replaces the barrel or you just run cast bullets sized to suit. The ad says you can run the same ammo in the rifle as your 1911 so maybe the barrel is changed?
Not my cup of tea but it may of interest to others. Got rid of my .45 LC guns but still have a couple of Kimbers in .45 ACP. Went with .357 for my pistol and carbine duo.