I have a 20 gauge 870 handed down to me. It was made in the mid 1950's. I would like to put magpul furniture and shorter barrel etc for home defense for my girlfriend. Does anyone know if this can be done? I have heard those years of shotguns use 12 gauge receiver etc. And I know there are adapters for 12 gauge stock. Will current replacement 18inch barrels etc fit on this gun?