O.K. then how would everybody like the Bank of Canada to start printing 1935/1937 and 1954 DF series again for the collector? They could print the complete series again for collectors. All serial numbers would have the original first issue prefixes with all zeros, and in the boarder of each note on the front and back have "CBNC or BNABN company 2006" and maybe another slightly altered aspect of the note to tell it's a reprint. All in UNC perfectly centered, would anybody be interested in buying those notes? They would use the same plates, ink, but paper would be different, again to tell the original notes from the reprints. The paper might be 50/50, 50 cotton, 50 pulp or they could put a watermark in the notes not found in the originals or use blue/gren or red security threads embeded in the paper instead or green planchetts.
Then you collect all those rare notes without having to spend a fortune for the originals. They could sell the notes 25% above face, or they could issue the notes as single sided proof like sets that are printed only on one side, you get the front and backs to each note. On the back the note would say non-negotiable" or watermarked like that, or not legel tender/specimen, then if that was the case, the notes could be bought below face value, i.e. buy the 1935 $1000 for $25 bucks. But the note would not be legal tender.