Slim Jim or California Holster provides a great uninterrupted canvas to carve. I made two of them for my Uberti 1860s. When I made mine I made the belt loop independent as opposed to folding over leather to create it. I sewed the belt loop on before I glued in the pigskin lining, it made it easier for me to sew the belt loop on. I hand sewed the holsters which included toe plugs. No matter how flawed our masterpiece is most folks will not even notice the flaws.
Hey Josh, thanks for the information. I have the Stohlman holster making book. Your completed rig provides a much better example of the completed technique.
I got my maker's stamp from Leather Stamp Maker (https://www.leatherstampmaker.com/home.html). I submitted my design to them. They worked with me to correct some design aspects to make it work. Prior to making the stamp they sent me a proof for approval. They made my mark out of brass, and they have a host of accessories to support using the mark.
I don't know if you are still looking for a pattern, but one of the members on this forum, Brazzos Jack, was kind enough to share a pattern which he created for the holster.