And it was produced by the American Bank Note Co.!
The back is very much like the backs from their popular Gold Certificates (1863-1934) though the orange ink is a bit brighter. I'm sure this note, if it were put in an auction, would get lots of attention.
I have never seen a Canadian banknote with such a bright orange back. Just looking through the BNM, all I can find is this
DOC P-37 $1000 Queen Marie specimen (1925):
http://www.banknote.ws/COLLECTION/countries/AME/CAN/CAN0037.htmso the Weyburn would be a "bargain" in comparison to trying to own a 1925 DOC $1000 (which I'm not even sure were issued).
I was just lurking on Reddit & I found these 2 comments about an obsolete Chartered bank (graded Remainder) printed by ABNC. The title was "Mexico doesn't make banknotes like this anymore"