[Bill A]

Simon has it. The Gaunt concern in Montreal made badges for the Canadian market. There is nothing in the record to suggest the badges went to the UK.
Dating is a bit more of an issue. The Canadian Grenadier Guards plain grenade badge, without the royal cypher, is not recorded in the standard references but other sources indicate it was worn by the CGG. It was worn around the time of the First World War, but the CEF battalion supposedly only wore a cypher pattern badge. (This has been challenged and research has suggested tha the plain grenade pattern was worn as well.) It has been suggested that the badge was worn post FWW as well. A similar badge (if not the same pattern as this one) was also worn by the 10th Royal Grenadiers of Toronto, and a plain flaming grenade badge was also worn by the 11th Regiment (Irish Fusiliers). The latter is supposed to be a bit larger in overall size.