Waste water tank repair help

[AZ_Gopher]

I have a 1981 Sundowner Elite mobile home that I purchased several years ago. I can't find any information about it online, so I am looking for any help I can get. There appears to be a waste water tank under the frame of the trailer connected to the sewer line. It looks like it may be fiberglass but I can't tell for sure. There is a small crack near the outlet of the tank that is seeping. Is there any hope of finding a replacement? If not, does anyone know the best way to seal up this crack? It would be easier if the surface was flat I know. I plan on keeping this trailer for several more years if possible. It is in good shape otherwise. Here is a picture. Thanks for any suggestions.

https://imageshack.com/a/img924/9913/qpwgSg.jpg

[Greg]

That's a new one on me. Is it possible that this is a converted travel trailer?
You could try some Epoxy or JB weld on it.
Personally I think that I would simply eliminate it and go directly to the septic tank.

Greg