Yes. We have a swivel base for $50.
My passenger seat can swivel toward the back. Cliff used a thick piece of plate over the existing bolts, and welded new bolts to move the passenger seat toward the center and back to the step up. You can contact Cliff for technical info. 919 345 9576 or he can send you photos of the plate. But we have a swivel base to sell that will fit your existing holes.