Steve, you’re probably going to have to find someone to fabricate one for you. Any original tank is probably fragile and cracked and probably won’t withstand the transfer from one coach to the other. I’m not aware of any new tank that is an exact match, but with some ingenuity, you could probably get a prefab tank to work. You might even be able to split the tanks into grey and black water.
I need to go down to All Seasons RV in Wenatchee WA. Somebody told me they were able to find the original manufacture and when they called them some old guy found the original mold. Don’t know if it is true but will try to find out.
Hi Steve Woods, There are a lot of grey tanks on ebay under rv grey water tanks. Or there is a guy in your area named Rodney. He has or has had a lot of parts & info. 253 202-4768 its been a few years since I’ve talked with him though. Good Luck, John68