Before you bite the bullet and buy those expensive cylinders, try honing yours. Is the cylinder you're looking for a double-ended one with two pistons? Those are fairly simple to hone, since the bore is the same size all the way through. The ones I was working on were blind holes with only one piston for each cylinder- - - -two cylinders per drum. Last resort- - - -send me the cylinders and I'll hone them out and make you some new, oversized pistons.
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!