I can only answer a few bits about the model / skin deviations from the real thing.
I had to make many realism cuts on (all) the models due to the limitations of the engine and the poly restrictions. It might seems like its an excuse but believe me its not. I reworked the SCAR model again for more realism tho. I hope its better in proportions and detail. (the few pictures that exist of it dont give away its actual shape very good imho)
I will look into the chargin handle thing again. I appreciate constructive help on the overall shape/detail questions.
The maya renderings are just glossy previews of the guns, no realistic representations. Making a bunch of realistic (photorealistic) renderings would take me all day and usually I just dont have that much time
No question everything we do is done is done under severe pressure and its hard to keep up with every little thing. Sho7 is doing a great job on the skins tho. Too bad that q3/ET shaders suck ass. Its impossible to get a decent weapon finish rendered in game, and believe me when I say we tried everything.