I have the harmonica rifle now. I hope to see the maker on Monday. I have taken some photos of the action at work and figured out how to feed the magazine in.
The magazine appears to feed from the left. The crank handle has to be rotated 180 degrees to the front and the magazine pushed in from the left until it stops. The handle is the rotated 180 degrees clockwise to line up the first of it's six chambers. A 360 degree clockwise rotation of the handle then lines up the next chamber. The rotation of the handle cocks the action(what appears to be a hammer). The steel box section that holds the magazine moves forwards and back and pivots slightly sideways as the handle rotates. The box section draws the magazine up against the barrel to seal them together for firing. The box section also carries a floating firing. I will try and load some images tonight when I get home from work.