Winchester loaded the .43 Spanish for a short while using the Milbank primer. Too expensive to section! I believe there is a drawing in the Guide to Ammunition Collecting in the Reference section. Winchester also headstamped the cartridge.
Union Metallic Cartridge Co. Berdan primed. These usually have the Orcutt reinforce cup inside, like your C above. UMC also headstamped these cartridges as shown below and on cartridges with an A base with U.M.C. .43-77. Did UMC produce this cartridge with the Orcutt primer ?
United States Cartridge Co. made this caliber with the Farrington primer. I do not own one…yet. Also in the Guide to Ammunition Collecting. It has been stated that they made cases for Argentina. These can be found with 93, 94 and 95 dates.