Imperial Gallic J - Robinson's mistake?

[Renatus]

I think it unlikely that Robinson has made a mistake. It seems clear from the text that the details that he describes were no longer present on the helmet, although there were presumably traces of them, or else were difficult to see. It is, therefore, probable that they simply do not come out on the photographs. Remember that Robinson held a senior position in the Armouries at the Tower of London, to which the helmet was on loan, and had the opportunity of examining it first-hand.