Canadian C/Broad Arrow Marking

[WpgBinocular]

Does anybody know when the arrow in a circle marking (see attached) replaced the traditional Canadian C/Broad Arrow marking and for how long this new marking remained in use. The marking in the picture is on the lid of the carrying case of an Optical & Film Supply 7x50 binocular reconditioned by C.A.L. in 1952 (the binocular has the same marking but with a X4 instead of X2 below the arrow inside the circle). I also have a type 1951 6x30 green web binocular carrying case dated 1953 with the same marking. Also, does anybody know the meaning of the IS and X2 inscriptions within the circle? This marking, by the way, does not appear on the Elcan 7x50 carrying cases indicating that by the mid-1970’s it was discontinued.

Frank Lagorio (WpgBinocular) - Winnipeg