RB made 5 original helmets for Lucasfilm in ‘77. (Photo below). Only one escaped the possession of George Lucas himself. Lucas burned one in the funeral fire scene of ROJ, and one was lost. Of the 3 known to still exist, two are well documented and in the archives and the remaining one is in private hands. That one was photographed in 77 for the ESB advance poster and was part of the original suit auctioned last year. It will not be sold again in the lifetime of its existing caretaker (who’s now 50). So unless the remaining one is found, there isn’t a way to obtain one.
BTW, the one in private hands, photographed in 77 for the ESB poster, was recently restored along with the suit. Here it is;
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Here are the five originals RB helmets in ‘77
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