Before we discovered Bolly props (and their adjustability) the "pipe players" "carved" their own custom props from existing stock. We scraped the trailing edge of the backs of the prop blades with the sharp edge of a straight cut piece of glass, or a # 26 Xacto knife. Do this until the 5 inch pitch measures 4.5, 4.75 or whatever...Then refinish.
FWIW
Ward