'68 M34 Water Tank Fill Hose Question

[dancrosswis]

Here's the short-version question: does anyone know how the "two hose" water fill actually connects to the fresh water tank on a '68 M34?

Here's the longer version:

I'm replacing the fresh water deck to tank fill hose. The original was in place and--frankly--disgusting. I've never used the tank. Upon removing the outer hose at the deck fill, I found a smaller hose running inside. The two were attached by a s.s. screw running through both hoses just under the deck plate. I opened the deck fill plate (for the first time). The inner hose just floats free at the fill plate. I.e. when filling the tank, I assume water could easily end up going down the inner or outer hose. Now, my problem is removing the hoses from the tank fitting. The outer hose is attached to a grey pvc elbow fitting that runs thru the chain locker bulkhead to the tank--which means I can't see the actual attachment at the tank. I have no idea what the inner hose is attached to, if anything. The pvc fitting appears ready to [twist/unscrew?] clockwise, but the inner hose appears to be preventing it.

Here's what would make sense to me: the inner hose just acts as a vent when filling the tank. it just floats inside the outer hose, with no fitting at the tank. The grey elbow has a screw fitting attachment to the tank.

Any ideas out there?

Thanks

Dan
'68 M34 Escapade