Open your catalog_sp.ymt and replace <model>W_REVOLVER_SCHOFIELD04</model> with <model>W_REVOLVER_SCHOFIELD02</model>

That's it. Enjoy your new revolver!

I included a clean catalog_sp.ymt with the edit in the optional folder, move that catalog to the ''Catalog'' folder (ONLY USE IF YOU DONT ALREADY HAVE A MOD WITH CATALOG_SP.YMT)