Having an actual M1A1 and observing 3 others vs the amounts of fakes or drop in's. I disagree there are certain wear characteristics that a M1A1 receives when in a paratrooper stock for a long time. These wear characteristics would not be on a regular inland dropped into a M1A1 stock. I can take some pics to elaborate. I'd likely just be showing the fakers and humpers how they can make their rifles more convincing but there are definite wear features to look for.
Please do show some pic's, very interesting subject.