GliderPilot, I have redesigned the latch for my own build to be very similar to that. However, I redesigned the main hinge block to eliminate the arc latch feature. This makes them easier, and less costly to machine. I also think its a more reliable, positive locking mechanism. The spring will be carbon fiber, which makes a great spring, and the catch block made of acetal.
I actually made quite a few modifications to the hinges. I removed the angular features. This also makes them easier, and less costly to machine. Mainly the main arm block. I do not feel it is necessary. I believe @Pdwhite done this to incorporate some sort of pressure angle into the hinge, which is fine, however unnecessary. That is merely speculation as to why he done it that way however.
I also redesigned the main body side of the hinges to be the same part. No need for left and right pieces here. They are fully symmetrical , and the same part which can be used in the left or right position. This also reduces cost, and eases assembly. This however also required an adjustment to the hole positions in the main body plates.
I also redesigned for round hoop tube. As I will be machining/fabricating all parts myself, this makes fabrication of the hoop much easier, less costly , and much easier to replace if needed in the future.
I also made several other minor design alterations.
I dont mean to jack your thread. Just nice to see other thinking along the same lines with the latch.
If you would like some carbon latches for that, let me know. I can cut them for you. While the plastic works, its probably not an ideal long term solution.