The Calgary Highlanders purchased green coatees for the entire regiment in the late 1950s - after the 1953 dress regs were promulgated. It is possible the bonnets appeared at that time also. Barry Agnew at the regimental museum would be a better source than I am. His contact info is on the front page of the Regimental website athttp://www.calgaryhighlanders.com
I'm curious now who the approving authority was for changes to dress regs - Quartmaster General? I think that when we added tartan ribbons to our bagpipes in the Pipes and Drums in the late 80s/early 90s we sought permission though the Directorate of History and Heritage or whatever it was called then?