I'll vote for
treadigraph.
The tipsy was prone to wing drop at the stall caused by reduced downwash at the tips due to its' pointed tips and no washout.
The slots reduced this tendency as did the later wing with washout.
I don't think the Monospar had wing slots.
Here's the Tipsy wing and the slots exactly match those in the unknown image by I42.
Since I42 doesn't know either would anyone suggest what we do now ?