The bronze filled bushings ended their life cycle in about 2001 or prior. They simply quit building themes replacements after going to the plastic in the 1990s. Having them built as a custom part for after OEM replacement parts, and for replacing the plastic, has been considered as have other avenues. BCB did have custom parts made in between availability. Swivel Eze is the part builder, not Springfield, and the lower base and stem pipe mentioned are machine lathe turned prior to welding. The lower and upper machined parts are glassed or adhesived into the front and rear floors. The forward front deck parts are also bolted and those parts could be available. The center seat bases are either lower mounted 2 piece mentioned or a 7″ x 7″ floor base that is fiberglassed into the boat floor. That should give everyone an understanding of the parts. BCB