I used a heat gun to pull an old long inside toilet flange out of an even older flange. I then cut the top of the flange off and am left with a thick PVC pipe measuring 4" OD and 3" ID. I guess this "pipe" is part of the original flange and I can understand it is an odd size but the pipe goes into the slab and down about 12" before there is a joint at a 90, which I'm not sure I understand what size that would even be if the OD is 4" all the way down? The toilet is 14" from the side wall so I really need an offset and it seems like I can not get a inside 3" offset toilet flange, and a 4" outside flange is going over an OD 4.5" pipe and this is only 4" OD. Is there any flange I can use for an offset here?