Doesn't the conversion plate need to have a spring-loaded firing pin in it? Seems like that might be the harder part.
One can use either a hammer mounted pin, which is rather long, or a plate mounted pin. If mounted on the plate,
One can order out pin/spring/cap screw assemblies as a replacement part . They are rather fiddley to make, but can be done on a lathe by boring out a piece of hardened screw and turning a shouldered pin. In that case I like using hardened screw theaded into the plate from the front (cartridge side) as that comes a recoil shield and can be sowhat larger in diameter. It does’nt need to be “too hard” since it is only getting pushed by the brass as the brass backs out of the cylindery during firing.