Well, you might try doing a google search from outside the forums and use terms like "vista view airforums." You should get several threads discussing rebuilds.
As far as thermal efficiency, I would guess it will have minimal impact if you remove the inner pane, as the majority of the windows in the trailer are only single paned anyway, plus the whole trailer is composed of highly conductive aluminum skins with an aluminum rib every so far along its length.
I disassembled my vistas, removed the inside pane, and used a piece of black automotive rubber hose to fill the gap and apply some pressure to the outer pane to help keep the seal. So far, so good.