Last year I bought this item from you and gauge is not working properly, please let me know which gauge I have to buy in order to replace it.
You would have to contact Airforce for replacement parts.
I bought this Refill Clamp and Disconnect it will not work on my scuba tank it will not seal air leeks around the clamp Is there a rubber seal on the clamp if so I did not get it
is this the correct item to go from scuba tank to benjamin marauder ?
Yes, it would work with a K valve Scuba tank and a Marauder
It isn't spelled out in the description, but I assume it's a Foster Valve fitting at the end of the steel hose...which means the Foster valve fitting (male) is on this rifle, also, correct? If that is the case then I'll just use my Crosman/Benjamin K-Valve yoke with gauge on this rifle, is not that correct also?
A Foster female, yes. If "this rifle" is a Marauder or a Discovery, then it will work. The Crosman/Benjamin K valve is similar, yes.