I don't know if this has been completly resolved, but I was reading my Dressing a Galaxy book, and they said that there were 6 Jango Helmets. 3 Dented and 3 Undented. I hope that solved everything. I believe that things got mixed up on the set and in post produciton. It happens, and I don't think they expected us to be studying each shot and each frame. Before I post this, I am going to double-check in my book...
Yes, indeed I am correct. On page 133, it reads in paragraph 1 lines 1-2 "Six full sets of this costume were eventually produced, including both dented and undented helmets..." So there ya have it folks. I hope that explains everything.