My factory installed skylight cracked also, but was delivered this way. I think they over tightened it at the factory. When Matt sent a new one to us, it was a single pane, not a dual pane. He said to just change the outer and it will be fine.
When I took mine apart, the inner and outer were sealed together. There was no way to separate them and every effort I made resulted in cracks to the inner one. Ended up installing the single pane and living with it.
While not positive, I believe this is the size you need:
Skylight - Neo-Angle - 27.0 X 14.5 Flange - White
I found it using google and searching for RV SKYLIGHT. Shouldn't be hard to find the one and color you need.
Personally, if I ever buy another RV, it will NOT have a skylight. Just something else to let in the heat and bust in the hail...
2014 Dynamax Trilogy 3850RL - South Hampton Interior, Full Body Paint (Black / Silver / White), MOR/ryde Independent Suspension, MOR/ryde Disc Brakes, ONAN 5500 Generator, Progressive Industries HW50C w/Dual Display, Winegard HD Dish w/DirecTV, Washer & Dryer, iSprings 7-stage Reverse Osmosis Water Filter, Trail-Air Flex Air Pin Box, Third AC installed, AC Voltage/Amp Meters, DC Amp Meter.
Retired USAF - Full Timers!