Looks like a heavily modded FAMAS with a MasterKey. I suggest you don't go through with the idea as the airsoft FAMAS is rubbish due to the Version 1 design. Not very good performance and if it breaks then you are screwed as parts are near non-existent.
Awesome idea, but to try to convert a famas into the Helghast assault rifle would be disasterous. Generally there the same shape but to get that to work would be a big hassle. Though I could see this created with an M4 reciever but it would deem the drum magazine costmetic. Then again a tube could be installed... Well I really want to make one now.
Electrical tape a UTG shotgun to a Famas, spray paint coffee cans black, and attach those to all of your mags. There ya go, champ No one will no the difference!
"Never Run With Scissors" Col. Jack O'Neill US Air Force......Two Ls