i found a pretty good solution couple weeks ago and still holding out. well the holding out will be known in under 5 mins after application. i have orings that have been running for a year now. i had to take bowls off because of gas leaks the whole year, i thought the inlet needles were all bad but the gas leak would form around all bowl joints where the orings go into. my bowl joints are all slighty bowed from over tightening oversized orings in the past, you can't bend them back either, bodies and bowls will have a gap. but onto the fix of reinstalling the "expanded" oring into the groves:
Place as much oring into a straight leg of the groove, clean and dry groves and orings are important, now take a piece of straight masking tap and only cover the oring to its edge with the clean straight edge of the tape, then feed the oring into the next straight leg, and with another straight cut of tape cover the oring just to it's inner edge, the last 2 legs start to push or cram more oring in and tape. once it's in, hold with your palm, and push the screws through and without scratching the bowl mating surface on inner side of the screw you'll want a tear in the tape for easier extraction. all around the bowl you should have tape extending out, you don't want to tape it to the sides of the bowl. mount the bowl and snug it flat to the body, when they are all in, turn the gas on, you shouldn't have any leaks, when the bowls are full shut the gas off and loosen the bowl evenly only enough so the tape will then slip out and not the oring. the tape, it'll come right out unless you didn't cut the tape or tear it. then youll have to wiggle it back and forth to get the tape to come out around the corners. it takes only a slight bit of a second to do the taping. it wont work for shrunken orings because there's no lip on the inside of the bowl groove. don't use any types of hardening glue like crazy glue in the corners, it'll work but then you'l be more prone to "cleaning the groove," that's when you'll possibly scratch the groove. you don't want to use anything harder than the metal it's made out of to clean it, and if it's dirty even plastic can scratch it. no scratches in the groove. don't use oversized diameter orings, unless everything is trashed. that sealing joint is designed to compress the oring so the groove will just be filled with the oring at the point the 2 "flat" mating surfaces come together. there's not alot room for errors nor scratches. slightly over sized diameter orings will bend the corners on the bodies and the bowls. if you tried to bend them back they'd break.