I have a set of four Marshall caster socket bases that came off a 1972 Marshall Bass Lead 4X12 cab. They are coarse thread and not the fine thread that most old cabs have. There were two kinds of threaded casters, fine thread and coarse thread. New Marshall casters do NOT fit into these caster socket bases and neither do the fine thread casters. I want $50 for the set with free shipping to CONUS. I accept PayPal and Venmo.