I have found in my mother in laws bathroom a damaged 4" closet flange as her toilet was rocking on one side. Her bathroom is on a concrete slab and the home is about 30 years old. The flange is flush with the concrete floor and the concrete is literally flush right up to the side of the flange and isn't typical of today's flanges, there is only an oval slot on the side for the tank bolts to slide in not like the key hole and slide I guess (slot and groove) I would describe the newer ones that you put the bolt in and slide in position, this you just put in the oval and basically turn the bolt so it doesn't come up. Well the one side has broken out completely so there is nothing for the bolt the grab on to. With the cement flush up to the top of the flange getting up under to put one of the repair rings is a moot point because there is only that little oval slot so there is no groove in the old flange for the bolt to slide into position if anyone understands what I am referring to and I am risking damaging the rest of the flange just to get access to under and around it. The Flange itself is actually in pretty good condition all around not rusted out, just that side keyhole has been damaged.

There is a product out called Push-Tite sold at home centers that is a PVC gasketed closet flange that says works for cast iron and or PVC/ ABS. Seems it fits inside the old cast iron pipe and is held in place by the gasket.
Has anyone ever used this and if so how well does this work?
I have also seen these Stainless steel closet rings that are secured to the old ring with adhesive and or to the floor with screws (wood floor) or concrete fasteners.
Has anyone ever tried one of these rings and if so what type of adhesive did you use to secure the ring?
I am looking for my best options or other options not listed above but am not looking to remove the old lead and install a whole new waste flange.
Would appreciate any help or ideas from anyone who knows more then I do.. lol...
Thanks Bill

Not seen a Push-Tite but do use Twist-n-set, its an Oatey product to replace broken flanges. You need to chip away all of the old flange leaving only the 4" drain. Slip the twist-n-Set intwisting once you are flush with the floor, they also make one with set screws inside that cause a gasket to swell, they bith work and here they are. Cast Iron Flange Replacement :: Oatey.com (http://www.oatey.com/Plumber/Shared/ProductGroupDetail/106/Cast+Iron+Flange+Replacement.html) and Twist-N-Set® Cast Iron Replacement Closet Flange :: Oatey.com (http://www.oatey.com/Plumber/Shared/ProductGroupDetail/363/Twist-N-Set%c2%ae+Cast+Iron+Replacement+Closet+Flange.html )

Thank you, seems this is my best option.
Appreciate it very much...