Well I can tell you that they are a normally closed, 3-way (exhausting) vs a 2-way (non-exhausting) button valve. SMG can supply valves with 10/32 thread, or 1/16 barbs.
SMG has these:
http://specialtymfgco.thomasnet.com/...=spec&filter=0
Clippard also has some that are similar but both are bigger than the BVM type.