Fixing up my boat, need a swivel seat

I have an old 1960s aluminum jon-boat. Its twelve feet long. In the center of the boat is an aluminum bench that runs from the left to the right side of the boat. Its about 2 feet wide and the width of the boat long. Previously I had mounted a fixed seat on a piece of plywood, then attached the plywood to this bench. However I'm looking for a simply swivel seat to mount on this bench. Something that I can bolt to a piece of plywood.

Any of you know where I can get a pretty basic swivel seat (either online or at a local store)?

As for fixing up my boat, I've decided to paint the interior with truck bed liner. Already have it stripped and primed. Going to paint the exterior either aqua-marine or metal flake blue.

There's one a wallywold that claps onto a jonboat seat and then swivels. Works good unless you try to lean back too far, like stretching your back, you and that seat will go tumbling on to the floor- or get wet :) Otherwise, you'll have to get a base plate and a seat seperately and mount them however you want. These are all available at walmart just go poke around the fishing/ boating section.

Where is LOCAL? I would suggest Stokley's Marine. They have a good base that you would put in a bass boat. Drill a hole about 2 inches wide 4 inches deep and bolt it down. If the bench seat is hollow you might need to reinforce the bench on the underneath so when you lean on it, it wont tear out. I did this on my old jon boat a few years ago and it worked well. Another idea is to build in a casting deck. Mine was from front of boat to the first seat back. Simply build Ribs or (Stringers) and then lay on the deck (1/2" marine plywood). Seal all wood with a good marine sealer and it will hold up just fine.