// I have read that the strengthening rib on the back of the crown on these helmets was done away with after the Model 1889 except on the officer's helmets. Is this right?
Then, in 1894, the M-91 side posts were added. Also, in 1912, the crown was lowered and formed a closer shape to the head of the wearer. Also correct?
My main questions are: who were the primary manufacturers for the issue Garde du Corps helmets, and when did the rib on the back actually go away? Were some makers still utilizing the rib during manufacture?
I have seen several of these helmets over the last year that had this rib but also had the M-91 side posts. This would surely make them post 1889. //.