This problem I posted under a different membership as I had issues signing in to my original membership name and joined up (again) to pose the question.
I promised the result of an RV repair shop finding, so here it is:
They could not reproduce the leak after filling the tank but when it was overfilled, the leak started. The tank was removed and it was found that the leak was coming from the tank inlet and there were two non-penetrating holes in the tank.The holes were sealed and the inlet joint reattached and copious amounts of sealant applied. I will not get to use the Pod until May, so whether this has been a rectification, I cannot say.
I want to thank ALL who made suggestions to my (other) person. The puzzle of how to drop the tank was resolved by one respondent but one requires a lift to work effectively beneath the Pod.
I went to a repair shop since they were better able to cope and I have a one year warranty on the repair. To have done it myself in the Great White North would have been too risky. Cheers.