The canopy latch mechanism has a lot of wiggle to it, moving left and right, into and away from the fuselage side. So I needed the latch arm of the new lock to be long enough to stop the canopy latch no mater where it wiggled.
In photo 1 you see I took the long straight latch arm and bent it. I then used the cut portion to rivet on top, forming a "T".
In photo 2 you can see the T blocking the canopy latch from moving backward (even if the canopy latch moves in/out, perpendicular to the fuselage side.
In photo 3 you can see the T in the UN-LOCKED position, where the canopy latch is free to slide aft or forward.
Latch arm with added horizontal.
In the LOCKED position (the canopy latch will not go backward).
In the UNLOCKED position. The canopy latch will slide backward and clear the lock cylinder.