The mask above was signed by Greg Nicotero, and believed to be R.A. Mihailoff as well but is hard to tell because it was so so damaged from sitting in a flat envelope for years. This mask resides in Japan.
The Mask above was signed by all of KNB EFX. This was a gift from KNB EFX to Tony Timpone the Lead Editor of Fangoria Magazine in 1989. This mask now resides in my personal collection and I believe is the best representation to how the Hero was in the film.
The Mask above was signed by Greg Nicotero and Kane Hodder. These pictures were of the mask when it was in my collection, however it now resides in Germany. This one was the giveaway mask from a contest that Fangoria Magazine held to promote the film.
The mask above, it is unknown who signed it. I have attempted to purchase this mask a couple of times, but always just a week behind a sale. It is located in the United States to the best of my knowledge.
New Line had KNB FX do the mask and effects for the film. According to Schow, the mask took a long time to get approved for the final look and the producers kept sending versions back until they could all agree on what we see in the film. It is believed that 5 total masks were made for the film, however that has never been confirmed. However there have been 4 production masks that have been verified and found, so that leaves the actual screen used Hero mask as the last to surface.
Each mask was signed by different people associated from the film