'74 20' CC fuel tank

[Ulf]

My '74 20'CC has no access hatch to fuel tank sending unit.

I would like to put one in, but not sure where to put it.

I just bought the boat this year, not sure if it's the original tank or not. The previous owner wasn't too helpful. The silicone around the big deck hatch does not look original, I'm thinking the fuel tank was replaced at some point?

The fuel tank checked out ok, I put a new Racor on it and ran about 50 gals through tank. Just changed Racor again, some sediment in bowl but no water.

Not sure what the capacity of tank is either.

Trying to get fuel gauge to work, hence the need to access to fuel sending unit.

Any help would be greatly appreciated,

Thanks,
Ulf