OK, final verdict:
The M2 screws from Amazon have too fine a thread pitch, and do not work well.
The screws Iron Sky describes do work, but will cut new threads in the plastic. May be useful if you strip the threads.
A new set of 10 screws from Yuneec Skins is 8 US$ plus shipping, they work PERFECTLY, because they are the correct screw.
One mo' time, here's the link: Top Shell screws for Typhoon H