I want to connect a WC to an old(ish) soil pipe. The old pipe is PVC, but it it has a wider than usual 130mm collar on it (inside diameter of the collar is approx 125mm). Just to add a little complexity the pipe emerges from the floor (i.e. ready for connection to an old style S trap) and in the wrong place (leading edge is 190mm from the wall and the back of the pan will be at 310mm from the wall).
The previous installation was bodged with what looked like a load of bog roll stuffed into the joint and used as a gasket, topped off with half a kilo of silicone sealant!
I was thinking a flexible WC connector would sort the distance and alignment problems, but what would be the best way to get a snug fit of the 110mm rubber fins into the wide collar? (the collar is attached to an elbow berried in the floor BTW).