Sorry to disappoint you but this is a total fantasy piece. Few metal badges were applied to the helmet and these were cap badges. What you have is a Victorian-era helmet plate attached to a First World War helmet. Victoria died in 1901 and the Brodie was not introduced until 1916. Clive
Gaétan, if I owned the helmet I would be very suspecious of it and treat it as such. I would not remove the badge just in case it was done legitimately for a purpose no-one has yet discovered. Personally I would feel like crap if I owned it, removed the abdge and then a year or two down the road found out that those badges were added to Canadian helmets for a certain event.
Adding more information. The badge is not a Canadian shako plate. The 29th, in Canada, was the Waterloo Battalion, but there is no such qvc plate listed in Mazeas. In the British army it was the 29th (Worcestershire) Regiment of Foot. It played a part in North American history, including action in the American War for Independence. BAD NEWS. The pattern of plate found on that helmet has been widely reproduced.
I own a NNSH MKIII with a helmet badge applied. I asked several NNSH Veterans about this,and they all said that the officers would do pretty much whatever they wanted. That being said,only one admitted he may have seen one like it.
As you fellows say above,who knows why they ere put there in the first place,could be an amazing story behind it.