I used tempered safety glass
Four years ago when I bought my 78h30, the lenses in both hatches were shot; UV damaged, crazed, yellowed, opaque. Being the handy pattern maker that I am, I made patterns and took off to the automotive glass shop where I had tinted, tempered 1/4" safety plate glass replacements made. Out went the plastics, a very good cleaning of the hatch frame followed and in went the plate glass with a healthy bedding of 3M Clear Silicone Seal -- NOT 5200!!No leaks, no cracks, no errors! Before you laugh, plate glass is used in a variety of major manufacturers' hatches -- I checked -- and the weight helps keep the hatch closed. I've bounced winch handles, tools, blocks etc on them and they've not given me any trouble. They are easy to clean and look great.If you decide to do this, remember to be sure and get TEMPERED SAFETY PLATE GLASS that is at least 1/4" thick and think about tinting it to. Oh, the cost -- about $80 for both pieces of plate.Good luck.