The printer can be determined by the layout or the FPNs, but the prefix cannot. In this case, you have a BABN sheet. (CBN used a 4x10 layout).
I would suggest closely examining the fronts of each note where the prefix would be on the back and see if you can discern the prefix that way. It may be visible through the note, or you may be able to read some embossing if it's particularly good.
Good luck.
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BWJM, F.O.N.A.
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