I recently picked up a new in box ban era (barrel date is January 1998) MT6530 Match Target Lightweight rifle. I noticed that this rifle had a stock storage door with a plastic latch and no hinge. This is the first time that I have seen one of these completely plastic door assemblies.
I did these two quick shots (below) of the stock storage doors. When looking at the head-on stock view, you can see the differences in hinge configurations and latches…the all plastic/no hinge door on the MT6530 compared to the more substantial door on my AR15A4 that has a metal latch and a hinge with metal internal pin.
I don’t believe the plastic latch/no hinge door would have much durability. Colt probably counted on the fact that these stock storage compartments aren’t often used in the civilian market.