Gray Tank Replacement

[frayfl]

I have an 06 Adventurer 35A. The gray tank was installed at the factory sitting on styroam supports several inches from the edges of the tank.
The lack of support has resulted in the sides of the gray tank sagging, and resulting in the top of the tank sagging downward.

The capacity of the tank is reduced due to the problem, the tank is not leaking but I am afraid it will start leaking sometime in the future so I intend to replace the tank soon.

There appears to be room to replace the odd shaped Winniebago,tank with a standard sized rectangle tank off the shelf holding tank. There appears to be enough space to replace the tank with a slightly larger tank. I am sure the tank from Winniebago will be very expensive.

Has anyone had there gray tank replaced and what were the parts and labor costs?

Also there appears to be a wire or tube entering the top of the tank. Any ideas on what it might be?

When the tank is overfilled grey water is leaking onto the top of the tank rather than backing u into the shower. I believe this may indicate a crack in the top of the tank.

Any thoughts or experiences would be appreciated.

Thanks Dennis