These are looking greeeaaat.
Should be official, IMO. Yoshi did say that TWI-quality stuff would get put into the game officially at some point, and, well, look. It's built out of TWI stuff anyway, sooo...
You should poke them about this once you're finished.
Edit: Btw, if these MP5 variants are going to the commando or something, will you consider bumping up the number of carried magazines to somewhere higher than 6? Especially considering that the MP5 is more likely to be fitting into the 1st tier (just speculation), and that's a tier with another weapon that has 50 rounds per magazine with like 10 magazines. In KF, 6 magazines will burn up reaaaal quick.
That SAS member looks real cool btw. c: