This is getting ridiculous. You are inspecting a mechanical device with movable parts. In order for parts to move and keep moving, there must be some play. In the scale of finger-operable levers and switches, this slight play can usually be detected by human hands. The play could be hidden by dampening with lubricants, spring washers, etc. but that is not practical everywhere and generally requires even more allowed movement in the design. Mechanical perfection (heh) exists only in lower-grade physics textbooks, not in real life.
On my generously bumped, scratched and who-knows-when CLA-d M4, I can detect various (tiny) amounts of play in all exterior parts that are supposed to move (I have sensitive fingers so that might help). Nevertheless, the camera works and is enjoyable to use.
If you can't overcome these concerns about your MP, why not sell/return it and get a well-used M3/2/4 instead? It would be relatively cheap and little deviations from the always unattainable Perfection would be normal and expected. Ergo, less cause for concern. Plus, you get the old-style materials, mechanics and finder optics.