Finely found an air tank that will fit. Bought on Amazon, made in China, had ten ports only needed four, could not get three of the ports to seal, ended up welding all the plugged ports. The new tank is half the weight of the old one (hope it last my life time). Installed with no air leaks, the fitting cost more then the tank, also replaced the check valve.
It is hard to make out, this is the out going air box for the generator hush box. It is installed on the bulkhead between the front wheels. This is way I moved/change the wet tank. Leaving tomorrow for a test run, to have Thanksgiving in Alva, CA