As for refitting the screen, use silicon grease, as used for plumbing, or vaseline. These will not cause anymore corrosion...even protect it to an extent. Do not use washing up liquid. It kills cars.
When I have fitted windows in the past I found that Waxoil is good because it does not react with the rubber and helps keep rot at bay. Alternatively KY jelly
is good as it is water based and evaporates quite soon after installation.
