Ok here's what I am thinking. I can repair the 6" x 7" hole in the plastic wall near the toilet(I'm guessing that it is ABS) by getting a larger piece than the hole to be patched putting it through the hole and gluing it from the inside. Then cutting another piece matching hole and gluing to backer piece. Then filling the gaps with something, sanding, smooth then epoxy paint the whole mess. The hole can be seen in the upper portion of the picture. I'm open and welcome suggestions as to glues, materials and process. Here's a link to the material I was thinking of using.McMaster-Carr
PS The floor repair is not my doing and I expect to rerepair!