Thanks Jason, I'd been looking at the first of the thumbnails.
Yep looks like someone really knows what he's talking about ![sad sad](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)
Why on earth would you want a reverser on a pump !
Though all my diving was done on compressed gas – air from a compressor or bottled helium, I did once get the chance to experience diving on a man powered air pump. Very strange as you hear each stroke and the atmosphere smells of neats foot oil. Any ex Navy diver on here of similar age would know too I guess. The deeper you went the more men required to keep the pump powered!!
No definitely not a model of a divers air pump!
Best – R