Me, I'd leave the Centaure as is being they, especially the one in question are among the rarer cap and ball copies produced. I'd do as has been suggested in other posts and buy either a Pietta or Uberti cap and ball revolver, conversion cylinder, and ejector if wanted. (I favor Uberti over Pietta, but that's a mote point). In looking at the two brands of conversion cylinders available, I'd prefer the Kirst with an ejector due to the R&D being a PIA having to take the cylinder off each time to reload. In reality, I'd just buy a Uberti current model Open Top or conversion model if cartridges are wanted to be fired. Decided this long ago in buying mine as by the time ya buy a cap and ball revolver and conversion cylinder and/or ejector ya have as much or more in dollars spent as buying a factory made model and don't have the need for any fitting. Someone else mentioned this also. Don't mean to toss mud on the people making and/or selling conversion cylinders, but do the math. I'm not as up on the Belgium made models as some, but as Long John has posted, you have one I wouldn't mess with and possibly ruin the value on. Just shoot it as a percussion hogleg and enjoy as is. I've thought of doing a Kirst Conversion on one of my large frame Dragoons some time as there aren't any conversions made by anyone using the big Dragoon frame and they are my favorite frame of cap and balls I have. Guess that would be the only time I'd go with conversion cylinder route. Just my thoughts.