I need a trigger return spring and plunger for my three screw .357. Gun Parts Corp. is sold out and Ruger refuses to sell these parts to me unless I send the entire gun back to them. They will, however, sell me the same parts for a NEW model BH. I need to find out if these will interchange or where I might be able to find them. Paying $25 for shipping a revolver to Ruger for a two dollar part makes no sense to me! Thanks!