Water Tank

[MLAW6993]

Wow, so much lost info in the old forum, but really glad to see this new site! Thanks to whomever got it going.

I have a 1994 Seaward 23. It has the polywutzit water tank that sits in under the v-berth. I've been fighting to get it fitted with new hoses for a couple seasons and cannot for the life of me figure out how to get them connected and then secure the tank from sliding around.
 
The forward, top side of the tank has two fittings. One for the fill hose to attach and one for a vent.

Option 1.
Pushing the tank forward, the height of the aft end of tank seems to prevent getting the tank forward enough to have the fill fitting forward of the horizontal surface of the v-berth. That is, into the anchor rode compartment. If I could get to this point, I could reach in with the tank in place and attach the fill hose and vent.

Option 2.
With the tank sitting more aft, the hose then must have enough slack in it to pull the tank back to a position where the fitting can be accessed. The hose would then dip below the fill line when the tank is pushed forward after connecting. This will retain water in the hose which I want to avoid.

Normally I'm pretty fair at finding solutions but this tank is driving my nuts. It appears to have been originally installed prior to the cabin lining and deck mount.

The pic/schematic of the tank is not to scale or precise. It has a more complex faceting but is just for general reference.

The second component of this issue is securing the tank in place once connected. Originally, it had a piece of cordage tied around it and pressed into a pile of filler. I think I might just 4200 a couple teak blocks in place to connect a belt strap. The tank itself is slicker than snot and nothing wants to stay in place on it.

Any help would be appreciated.