Important question(s) Wyn. There was some stuff going around about the "dots" between the motto being a characteristic to determine the date, but I can't remember which was which.
The only bi-metal badge in my understanding is the officer's badge. And my understanding is that the officer's badge was only well after WW1 and on. (See the
Royal Montreal Regiment badges in the Canadian Badge Registry.)
Jo, I stand to be corrected on this, and I will have a look, but I think I have Scully marked R M R badges.