Don't know much about an air operated vacuum pump. I have seen people solder a brass fitting on the suction line of an old refrig compressor and use it as a vacuum pump.
An old friend made my vacuum pump, about 40 years ago, by using a vacuum pump off an old diesel engine. Belt drive and it has a 1/4 hp motor. I think the belt vacuum pump may have been used for the power brakes, not really sure. It worked well for me years ago when I needed to suck down an AC.