Hello Greg, if you are still looking for an extension ring for your bronica, I can offer both automatic rings g-18 and g-36, but I am afraid that the price perhaps will be a bit higher than expected because they are brand new, from a clearance in a local shop in Barcelona (prices in Europe are quite high). I am asking 220 euros plus shipping (20 euros) for one of them, or 420 euros both. I accept paypal.
If you are interested, I also have brand new 50mm (550 euros), 65mm (450 euros) and 150mm (400 euros) lenses and some film backs, finders and other accessories, all new, for bronica GS-1 and smaller bronicas.
I am both a photo collector and film user, and also buy and sell thing in Ebay (my id is jbpcamarat, 100% positive rating).