seating a one-piece back tank/potty/shower combo

[Aktundra]

I currently have the shell off a 1963 Bambi and sitting on cinder blocks, and the frame flipped over and preparing to rewrap a new belly pan. I have the original fiberglass potty/black tank/shower combo, shimmed up from the bottom so I can layout the below floor plumbing before I close in the frame with the new belly pan.

This is just a rough fit for purposes of routing the plumbing, but I can already see that the underside of the fiberglass pan is pretty uneven compared to the "laser" level plywood floor.

Weeks way from flipping the frame back over, dropping the shell back on, and really re-installing the fiberglass pan. But was wondering what will be the proper way to reinstall the fiberglass pan, and have it properly, evenly supported from underneath ?

[DanielB]

define "uneven"

[Aktundra]

Well for starters, the drain in the shower floor is at the lowest point, so the whole unit rocks on that point. Likewise the drain in the bottom of the backwater tank is at the lowest point. however there is a hole in the floor for the blackwater drain so this is mitigated.

It looks like when it was originally installed, there was some kind of foam sprayed around the hole in the floor under the blackwater tank, the unit was "potted" or seated before the foam hardened and it cushioned/evened the pressure under the back area, not sure if there was something similar used in the front under the shower area.