Just wondered if anyone recognises one of these?Thought it may be ok for airbrush etc as its quiet.Its a Binks Bullows Type L from 1967.Tanks maybe 20 litres.2 1/3HP motors.It runs ok but isnt pumping a lot of air into the tank probably because both pumps have 2 inlets/outlets that havent got any fittings in?Pumps are linked.Left one goes into the tank and the right one has some sort of filter/blow off assembly?Sorry about the shaky picture I can do a better one if necessary.Can anyone suggest what goes on the 4 threaded ports?