Douglas today can't identify what it is small flat piece of metal with the words "degrees of know" any help would be appreciated.
is written backwards on there like it was to be stamped on something
I agree on it being some sort of printing plate from an offset machine. This theory is a stretch but... the "degrees of know" might be short for a second plate with the rest of "know(ledge)" which may refer to a known epistemological text authored by Jacques Maritain in the 1930s and this plate may be an English text version for something on what I presume would be the title page or something.
A new translation (in English) come out in the late 1950s and just by looking at the font type of the plate, that was a popular style (maybe Courier) at the time for academic works.