And then there were Kirst....
Don't forget the newest Kirst product, the Civil War series looks like a percussion cylinder and uses a single firing pin. Only made for '58 Remmie clones by Pietta & Uberti (so far ,I really wish they'd make them for Colt's open topped percussion clones !) .
http://kirstkonverter.com/shopcontent.asp?type=remington1858
-look on the bottom half of the page-
and you can purchase it here:
http://kirstkonverter.com/shopdisplayproducts.asp?page=2
and there is also thier "Pale Rider" series of un-gated konversion cylinders that you'll find marketed on those same pages,
I just really prefer the Kirst way of doing things, and felt that thier product line of un-gated cylinders should be represented here as an alternative too.
I'm going to get a gated version for my stainless '58 Pietta , and a single Civil War series backplate along with a cylinder for each of my 5-1/2" Pietta '58 and the Uberti '58 revolving carbine. Same backplate for either gun, it just requires a suitable cylinder for either brand.
With the Kirst, you can use a short OAL .45 Colt in thier cylinders, The Howell/R&D/Taylor product isn't long enough, you have to use Schofeild ammo with thier cylinder.
Kewl stuff!