Just a toilet FYI:
Before you start ripping that raiser out. Just keep in mind that an RV toilet is WAAAY lower than the standard toilet in your house.
That is why most of us put it on a raiser or buy a new one toilet that is taller matching a house toilet height.
There is a chance that the previous owner bought a taller toilet AND put the raiser on it also. But I would measure the toilet first.
When you go to sit down the first time on a 'standard RV toilet' your body is so used to the toilet being a certain height in your home you just about fall down on to it because it so much lower. Just saying think about that. :W