Originally Posted by jan61
Thanks for all the ideas. we have tried inland rv but no luck, we will try inca plastics today went to their web site hopefully maybe. We cant patch it cuz its way to far gone. Its kind of like dry rot plastic.
Trying to help you, without any drawings or photo's, is near impossible.
Posting a couple of photo's with dimensions, will get you several ideas, if not the tank as well, or at least a reasonable substitute.
We have many drawings of old Airstream water and holding tanks, but not the one you need.