Shower Pan in 1978 Argosy Motorhome

[Belle]

Does anyone know the material used to make shower pan in a 1978 Argosy / Airstream motorhome? ABS? PVC? PS?

We want to repair a small crack in our pan and I've searched the forum and found numerous options, but they were varied. Figured the best place to start was to determine the actual material used to make the pan.

Weld-On #16, now made by SCIGRIP appears to be one option that might work for us and works on multi surfaces, but still would like to know the material we are working with. Has anyone had experience using this product?

Thanks in advance.