Hey folks, I picked up a 1966 vintage Ruger Standard pistol at the gun show over the weekend and now need to find some parts. First on the list is the bolt. Does anyone know if the Mark I bolt is interchangeable with the Standard? What about the Mark II? I understand the mainspring housings between the Mark series of pistols is interchangeable, but has anyone ever taken one apart to change springs and reblue it? Thanks!