I noticed in Bubba Brown's Creole Stomp video that he played a Sterling with the #3 stop down. Hohners have a wet reed set in that position, and to play it dry you just close that register.

If that is the case with Sterlings, Monarchs, and other old German boxes, then you had wetness on demand. The result would be tuning as varied as the song versions to suit the mood of the day.

Excellent observation.

And when boxes went out of tune...so much so it was difficult to determine a "base"...
the second set of middle reeds , over time< were often tuned to match the "440" set.