This issue of Tokusatsu Hihō had an article about the Redman costume reproduced in 1996 when the laser disc box set of Redman was released.
The article says Yutaka Narita who was with Kaimai Production then sculpted the new Redman costume while he seems to have made the masks of the recent Ultamans since Ultraman Tiga.
Narita (it is unlikely that he is a relative of Tohl Narita) says in the article he sculpted the mask based on photos of the original Redman Tsuburaya Productions provided him with as the original costume didn’t remain in existence.
According to Narita, the eyes of the new Redman suit were duplicated from those of Ultaman Great.
Confusingly enough, this issue of Tokusatsu Hihō also had some photos of the Redman mask in the frontispiece described as the one used when the show was filmed with the caption “Ōoka with a smile happy about the reunion with the mask used back then.”
Besides this, a caption says Toshio Kaimai, the current president of Kaimai Production, stated that he feels like they tried to find out the original mold of the Redman mask in their storage when the new costume was to be sculpted as it is likely that the original suit was made by Kaimai Production.
Then it should mean that the original mask photographed with Ōoka in it was found out quite recently at least after the new suit was reproduced???
The one held by Ōoka properly has the glitter eyes just like the costume used in the show while the new one made by Yutaka Narita had the eyes just simply painted yellow with gloss. Therefore the mask Ōoka holds should be the original one used in the show while it is so confusing.
Redman was acted by Kinichi Kusumi (1950-present) who also played Mirrorman, and this issue of Tokusatsu Hihō also covers an interview with him I would like to talk about if I have an opportunity some other time.