Trying to add some attachment points to a plastic tractor cab

[WCarpt]

I need to add two more attachment points, to fix a poor design, one each on the long side in the center between two existing points to a plastic material on a cab of a tractor. Since the manufacturer did not properly space the bolts that attach an access cover to the cab, the thin plastic access cover ~0.1 inches thick bows substantially between the bolts which are spaced 16.5 inches apart as a result of the pressure of the ultra-soft neoprene sealing gasket (.75 inches W x .5 inches H) which then creates a sealing issue. The plastic material at the front of the access hole is 0.150 inches and the plastic thickness at the rear of the access hole is 0.137 inches thick.

Does anyone have any ideas to resolve this issue? I have thought about gluing either a metal or perhaps plastic piece .75 inches wide to the underside of the cab but the glued surface area would have to be made to conform very closely to the curved lip at the edge of the hole so the glue or epoxy would hold well.

Does anyone have any suggestions on how to resolve this problem? See photos.

 

[Dumber than lumber]

You could epoxy some blocking inside there.
Wood or aluminum. Instead of epoxy you might use 3M 5200 or similar.

 

[Spencer Was Here]

Apply weight as needed to compress the gasket uniformly before securing with the fasteners.

 

[BD1]

What about adding flat stock or angle to the top. Drill holes in angle, set on top, and fasten down. You can get 1/2''x1/2'', 3/4'' angle , or 1/4'' thick flat stock.