I treated and primed the landing light mounting plate. Then I visited the 7th ring of hell (my yard) and I mowed it. After being resuscitated, lots of water and a shower, I continued with the landing light. I pretty much followed the instructions step by step except that I didn't follow the recommendation to leave the inside upper surface unprimed. The reason to leave it unprimed is that light reflects off of it and does a better job of lighting up the area directly in front of the plane. I think this is outweighed by the increased chance of corrosion in this part of the country so I primed it.
I put in the weather stripping between the lens and the leading edge skin. There is a pronounced lip all around the lens that has to behave like a small stall strip. I'll try it without the weather stripping later.