JD Air Parts offers some really nice items for the RV-7 series. I bought their canopy latch system, along with their fuel vent and fuel drain covers.
Their canopy latch system is a huge improvement over the flimsy latch that comes with the stock RV-7A kit. Looks better, much stouter.
I removed the old latch from my aircraft, and drilled out the two rows of #3 rivets that held those angle mounts to the aircraft side skin. Then, following the JD plans, I cut two lengths of 0.063" x 3/4" x 3/4" angle for the mounts.
I used the top row of existing rivet holes on the fuselage skin to match-drill the top angle mount (images 1 and 3). I then measured/drilled bolt holes through the angle for the two latch pieces, using the pieces as guides per the directions (image 2).