Thanks AnEv942, I was thinking on my way into work this morning that they may be the winter drains for blowing out the lines. I did see two shut off valves inside the shed door.
I started the icky job of the toilet today. Wood was destroyed. Most of the water damage on the camper came from the two $5.00 plumbing vents on the roof. The caps and parts of the flanges were completely destroyed. As you can see in the pictures there was nothing left of the wood.
FYI...when pulling the flange from the floor. Where in a normal residential install the flange is simply screwed to the floor with a rubber collar that extend into the pipe, on a camper for a tight seal the flange is threaded into the tank. Makes sense now but for the two minutes or so that I was prying the hell out of it, it made no sense at all. I'm lucky the tank is flexible or I would be JB welding it.






Thanks for the picture size tip. Got it!
Kindest regards
Ed