John Osborne signed Bank of Canada notes only until 1938, when Donald Gordon replaced him as deputy governor, and that short window is where the 1937 series hides its rarities. The hundred shows it best: 70,000 Osborne notes against 4,170,000 Gordons and 900,000 Coynes. Same Macdonald portrait, same sepia note, same everything - except the pen, and a sixty-fold difference in the count.
This is the file's cleanest lesson that on the 1937 series the signature, not the denomination, is where scarcity lives. A collector can own the bilingual hundred for the price of a nice dinner in Gordon form; the Osborne is a different market entirely.
Read the left signature before anything else on a 1937 note. Every denomination has a cheap form and at least one expensive one, and the difference is two cursive words that plenty of listings never photograph properly.
Mintage figures: United States Mint (Annual Report of the Director of the Mint), Royal Canadian Mint records, and — for the 1935 banknote issue — Bank of Canada printage records as published in the Charlton Standard Catalogue of Canadian Government Paper Money, cross-checked across independent published references. Specifications: United States Mint coin specifications.