How is the black tank held in place in a '64 Globetrotter?

[Globie64]

I'm replacing some of the flooring under the bathroom in my GT, a patch rather than a whole rip out the bath and redo, at this point. The black tank appears to be held in place, or had been, by two pieces of 1" plumbers tape slung underneath it. Those are gone, and my next project is to take the belly pan off under the tank and weld in place some steel strapping to support the tank, Any thoughts are welcome. Pictures to follow.

[64Lincoln]

There was a sheet metal cradle that the tank sat in. My was quite rusted, but there was still enough metal there to securely hold the tank. I don't know if plumbers tape would give it enough support or if it needs support. It seemed quite ridged to me when I was working on mine.