That toilet is actually called a SaniWare and I have a couple of parts diagrams for the 300, 500 and 600 models. Do you know which model you have? Maybe a picture or two would help describe your predicament. I hope these help.
4CU 2699 / AIR 10 / TAC AZ-1
I'm haunted by aluminum.
Charter Member of the 4 Corners Unit.