19' Front Bathroom Scamp Toilet Flush Valve not fully Opening

[Tcjmiami]

I remodeled my 1987 19' Scamp Front Bathroom.
I replaced the Shower Pan and used Fiber Reinforced Plastic for all the walls.
I Rotated the Tank/Base of the Vacuflush to the original orientation and since then the ball valve does not open more than about 1/2 before the pedal hits the Tank.
The bathroom had been butchered by the previous Owner and I do not know but assume that the vacuflush is the original toilet.
I have replaced the ball valve, spring and seals twice and there was no change.

Does anyone know a solution?
Is the tank different on the front Toilet?
Is the flush lever (Called cover) different slightly different in the photos?
Is there a modifacation that I can make?
I am attaching photos of mine and a newer factory front bathroom toilet.
The first two photos are my toilet the second two are from the newer 19' front bathroom scamp.

[Eddie Longest]

You have a Dometic Sealand 711M28 toilet. The flush leaver has to be above the low part of the top of the tank. Your tank needs to be turned 90 degrees if you want the bowl facing the way it is mounted. This means replumbing your vent and drain. One other option may be to try to turn your (black) flush valve section 90 degrees, but that requires you to replumb the fresh water and the flush pedal would mount across the front of the toilet.
Eddie