Protobabble:
                This is one of those guns which I don't which name is right.  It might of been that one was the complete gun, and the other was a conversion kit.  Mostly I have seen it called the Mk.III.  As far as being marketed, it may not of made it out in great numbers, but I'm confident it was sold on the retail level before REBLine closed their doors.  I seem to remember a letter in Action Pursuit Games, in which the writer sent in his gun just before they closed their doors.   The reason he sent it in was he couldn't get his Mk.III to work properly.  I list the issue as soon as I find it again.