until Thusday when I get back to check my impitemchoices files my thoughts would be:
1) impitemchoices are out of order possibly, move 942 to the correct (second) place in the list after the helmet.
2) place your belt buy option as the next one. curse loudly if it is out of sequence.4) check the RH column of options in game case it is not showing by default and you need to click on the drop down to bring it up.
5) choose NO skills/attributes. nothing should conflict - probably doesnt anyway.
6) let the imp choices exceed the actual items....something about guns and ammo inherent to any weapon you get and probably unnecessary.

I really hope it works 'cos I know just how maddening it is.
BTW I could not get it MG42 to appear with an AIM until it appeared with me. then we both had it. Prior to that it would appear as selectable in game but not appear with the imp when game lunched.