Next step was to decide how to hold the lens on. Instructions say use one screw per side or 2 per lens. I looked at other RVs at Arlington this summer and saw some with one screw, but others with multiple screws. The ones with multiple screws seemed to have slight puckers inbetween screws so I decided to use just one screw.
I drilled it and riveted on a plate nut.
I countersunk the liens a bit to accept the flat head of a screw so it would fit flush.