Try and dry it out on a radiator.
We did this with aircraft windscreens when there was an ingress of moisture. Normally the windscreens have some tubes that contained silica gel attached to them that 'breathe' through the silica gel crystals and keep the air inside the screen dry (they were double skinned windows in the cockpit on the HS125). But sometimes in really bad weather or if the silica gel wasn't changed soon enough for fresh stuff, moisture would get in and 'steam up' the screen. The fix was to leave it on a warm radiator for a day or so, and while it was warm fit a fresh tube of silica gel crystals.
As for re-sealing I have discovered a really good adhesive/sealant
HERE Not only does this stuff seal, it bonds things together really well. I've used it instead of rivets on some strengthening plates on the inside of my vintage car mudguards, where I didn't want crud getting behind the metal or rivets spoiling the lines of the mudguards