Make your own.
Get an old steel frame, has to be steel.
Make sure it has a seat post, and seat.
Take every thig of the frame, wheel, brakes, crank, etc.
Cut the frame, cut the top tube where it meets the seat tube, cut the down tube where it meets the bottom bracket.
Spread the rear section so the drop outs are about 18 inches apart. Toss the rest of the frame.
reinstall the seat post and seat, adjust the height and angle. And there you go, custom bike themed shop seat.