CL46ii FFC -
The signature on the stamp above is from the hand of the pilot who made the first flight, signed "A. Malone, Pilot". Alva Malone was one of two pilots.
The stamp is a CL46ii. The CL46ii incorporates CL46i ("Snow on Wings") which is caused by a colour shift. Also notice the shift in the maple leaves. Also incorporated is CL46a. CL46a involves a serif on the crossbar of "A" in "AIR".
Finishing off with a nice split-ring cancel from LAC LA RONGE, SASK on the reverse.
Also, the stamp is on the address side of the envelope, not the back where it was supposed to be.
The approximate quantity printed of the CL46 was 2,400. They were printed in sheets of 200 and panes of 50. I'm not aware of the exact number of CL46ii still out there, but the numbers are probably somewhat limited.