Since you did not reply to the problems I highlighted in my review, I have decided to try to solve some of them on my own. Like you I am not a mechanical engineer (electronics, yes) and like you I do my DIY project via trial and error.
The first and most important problem is being unable to rotate tuner past the String Drop. This results in having to loosen (or remove, depending on guitar) the tuner nut to move String Drop out of tuner key's way.
The above image (double-click to enlarge) shows how the mounting of the string drop interferes with the tuner key. We see a curvature of the mounting plate, partial caused by the bend in one tang (designed to act as a spring washer?) If there were no curvature and the plate was parallel to headstock, the mechanism would most likely clear the tuner key.
Putting the tangs under the tuner washer, does not guarantee that the mechanism curvature would be reduced and would actually bring it even closer to the tuner key.
I can bend the tang UPWARD instead of downward.. But here I assume the bent tang is a design point (act as spring washer) and not a manufacturing defect. That was not confirmed.
If it IS a manufacturing defect, I can flatten the piece in my bench vise.
Your comments on this issue would be appreciated, as it affects String Drop usage on all Martin-style headstocks..