Print all parts flat. Clip “Stand_hook” into “Stand_low” and secure with cyanoacrylate glue.

Use the registration marks to clip “Stand_back” into “Stand_hook” and glue with cyanoacrylate glue.

Add the mirror retention clips with M3 screws, loose enough to be able to flip them on/off.

Tap the three M5 holes with oil, and use preferably nylon-tipped screws as adjustable feet.