I tried to do it using the method you mentioned and was unable to make it work. I tried several different adhesive without positive results.
Putting the glass on the wood first made the panel too stiff, it wouldn't conform to the curve of the front. Stiffness being the whole idea in "plywood", that extra 1/16" of glass made the 1/8" plywood too rigid for my use.
I then tried putting curf cuts about 1/8" apart which didn't work either.
I had to put the 1/8" plywood on the camper and then put the glass on the plywood.
That being said, I was using polyurethane adhesive which could have been the problem. I didn't try contact cement which may have some give to allow it to bend. Polyurethane works well for bonding fiberglass to other surfaces because it doesn't need air to cure.
Once finished, everything turn out great. Hope yours does too.
Keep us updated with the result.
