The only advice I could offer, and I'm sure you know this, is to find where it's leaking from. Ya I know - easier said than done....But it may be a very simple fix.
I guess some water with food coloring may help you to locate the leak and then try and fix it. I know the issues with NRV, I own a SeaView and have taken off panels just to see what's inside and under the bed and I'm glad I don't need to work on the tanks. I was told that to remove tanks may involve removing the rear end cap.
Anyways, good luck and keep us posted. The work you do could help save others with NRV products.
OBTW - There's a NRV newsgroup on yahoo. You may want to try there.
-paul