The power is going to be a function of the vacuum piston diameter and the bore of the fluid cylinder. The bigger the vacuum piston and/or the smaller the diameter of the fluid bore, the more boost will be produced. If those dimensions are the same, both units will have the same amount of boost. NAPA stores usually have a selection of new or rebuilt boosters that would probably be less hassle and/or expense than trying to repair what you've got. The tricky part will be finding an old geezer who can still use a paper catalog!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!