Fresh Water Tank Access

[Badco8]

My 76 AS Sovereign leaks around the front edge of a large metal box framed square section in front of the wheels. It hangs slightly lower. Being a new first owner of an older AS, I am assuming that this is from my fresh water tank. Is there an overflow or vent and is it leaking due to too much water or possibly leaking thru the small holes that some models have for heat from a blower pipe from the furnace? Is there an access door in the floor inside?
Please where do I start. The whole plumbing layout is a mystery to me.
I guess that being an older tank, I should consider total replacement and also to the grey water and black water tank.
Please!!!!!!!!
Some good logical advice and links to helpful threads with drawings & explanations.

[Fyrzowt]

Welcome to the forums!
It really depends on where it's leaking. My '72 was leaking at the fill tube just inside the trailer and was leaking down into the square area you describe. It MAY not be serious, don't panic yet.
If it turnes out to be the tank, there are others here who have done that and can advise you.
Good luck,
Dave

[Badco8]

Thanks Dave