Coinsandcanada.com

Are all 1937 Osborne and Towers one dollar notes considered narrow panel?

Yes

That is correct: all 5 prefixes of the Osborne Towers 1937 ONES are narrow panelled but not labelled as such (since there's no variation amongst the 5 prefixes).

They're only labelled narrow panelled on the first 2 prefixes of the Gordon Towers ONES. That's b/c the design was still narrow panelled for the full run of H/A & 1,028,162 of J/A.

The design had a widened signature panel for K/A onward (& all the subsequent prefix variations: A/L to Z/L plus A/M to N/M). That's what makes the H/A & J/A highly sought after as they're tough (H/A) to scarce (J/A) & represent a "drop in the bucket" compared to the # of wide panel signature panels. It's much easier to find an Osborne Towers in UNC than a Gordon Towers H/A (& near impossible to get a high grade J/A).