also check Richelieu Hardware web site. they have lots of items that might work for you. Here is a link that might be useful: richelieu

Thank you for your considered and thoughtful responses! As far as explosive sewer gas, appreciate the warning but, as stated, already torched the vertical "tailpiece" and removed it. With respect to fernco fittings, I looked at these and found eiher a no-hub "sleeve" type connection or a "donut" which fits inside existing pipe. Doesn't seem the no-hub sleeve would provide the stability you would want and, at any rate, it does not fit over the coupling (hub) on the closet bend. The donut is designed for cast-iron pipe and will not fit in 3" coopper hub. Box-store people had no idea how to fix this as they are familiar only with cast-iron or PVC setups. I bought a new copper flange and was lucky enough to bump into a plumber at the supply house who gave me a few inches of 3" copper (10' of 3" is super expensive!). I resoldered this new "tailpiece" into the existing closet bend with my little propane torch (sorry again about torch and sewer gas, but too late). Hoping and praying that this joint holds up. Now I need to attach new copper flange - now you've got me worried about soldering it on. Hope anyone else who has to deal with refitting to copper closet bend can benefit from your comments.

Thanks for the suggestions everyone. I figured that since a fat wax ring didn't hold the first time, some kinda extension was in order. The home center didn't have any kind of different ones, just about 1/4 thick hard plastic (like the pipe). No kind of seal on it so I figured a little silicone wouldn't hurt. When i went to clean up the orginal cast flange but some of the pipe was sticking above the flange. It wasn't the cleanest cut (even for cast iron) not sure why it would be like that. Took a grinder and removed the excess pipe and clean up the flange surface. Then a little cleaning and silicone and the two extenders. let the calk dry good and put it all back together. No leaks yet! Kid keeps clogging it with too much tp.

Sorry, I meant purchasing the glue-over model that's made for this. I didn't have to cut out the flange in my case. (no leaks) But to cut it, sounds pretty easy. (PVC, right?) Use a mini hacksaw and carefully cut around. Or use a jigsaw with a fine tooth metal blade. Go slowly.