Aw Cummon (come on?) back at ya.
Funny that what some people, (you) consider to be "a little care and attention", others myself included, consider to be a PITA.
Sooo much simpler to use a bottle neck cartridge that was designed to work in a blackpowder lever gun by engineers long ago in a land far, far away. Case rim unsuitable for a rifle extractor? Really? Apparently that ones been figured out by modern, more smarter engineers. At least the OP didn't put "long Colt" in his post!
More discussion Coffinmaker Sir?
Respectfully yours, Broken Nose Scotty