Those valves are likely made by Halkey-Roberts (sp?) and appear on many dinks. West
Marine has many different pumps, and lists separately the twist lock nozzle for these valves. We had
lost the one that came with our
dinghy, couldn't find one anywhere here in Oz, but were able to order one from West. There are two different ones that I know of. They are the same diameter, but have different "depths" to the bayonet ears. We got the wrong one, but were able to use a second thick rubber washer to make up the difference and it works ok.
Cheers,
Jim