You remember right, Alvin- - - -it was not uncommon to repair a piston with a worn ring land by using a special cutter to square it up and putting a spacer under the ring to get the clearance right. The middle ring is called a "scraper" ring, and it seals compression on the upstroke and twists to scrape any oil the oil control ring missed on the downstroke. It's not uncommon to find a tensioner ring behind the scraper on some ring sets, especially on heavy duty truck applications.
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!