Lowe's guy said it was Oatey that made this pvc connection from bottom of toilet to pvc pipe. There were no replacements at Lowe's. I just remodled the floor. Oatey couldn't help me when I asked for a part.
I'm afraid you are going to need to chop up the floor to install another elbow and flange. There is no two ways about it! The toilet drain has to be affixed to the effluent line and the flange needs to be screwed to the sub floor [wood or concrete] you may get away with a bowl adapter and a wax seal with a reducer cone, but that connection will never be "up tight."
I looked into a few areas and what you have left in your floor seems to be the wrong drain. Look at your pictures. you have an elbow with three spots that accept a bolt in flange typical of a shower drain NOT a toilet flange. A toilet flange glues directly to a coupling or an elbow in your case. Like I said before you're gonna have to chisel out that pipe and replace it with the proper extension and elbow AND toilet flange.