Robin, see if you can find a copy of the CFP for Grenades and Pyrotechnics or just seek on line.
https://www.scribd.com/document/1162...nades-and-Pyro
Or
https://vdocuments.mx/canadian-force...otechnics.html
The secondary use of the tins would be for holding packettes of suger/coffee/creamers after the contents (smoke grenades) had been thrown so they still have a role with your vehicle today if you are going for the lived in/in service look.