Flashforge Adventurer 5M (AD5M) / Pro Z-axis cover and PEI bed plate fixer holder

Sorry for the long title. I've made corners ( https://www.thingiverse.com/thing:7330019 ) for the PEI plate before, but it was inconvenient to remove and install them each time, and it was also difficult to store them inside the printer or lose them around... So, I decided to make them hinged. Many thanks to @dark256_2767021 from printables for his Z-axis cover project (ID 1288447). I didn't redesign them from scratch, but simply added a tab for attaching the corners. I made the corners myself; they require support (see the images for placement on the plate).