I got ahold of some intel for anyone looking to make scale AV's.
SE5 2-bladed Tractor For 150 HP Hispano Suiza Engine
Drawing No. T28066 Issue 5, Dated ?? Jan 1917
47" radius (7' 10' diameter + or - 0.20")
Included on the drawing is the comment "This airscrew is identical with T28086 except for boss."
SE5 2-bladed Tractor For 200 HP Hispano Suiza Engine (Gear Ratio 3/4)
Drawing No. T28063 Issue 1, Dated ?? Jan 1917
52.5" radius (8' 9" diameter + or - 0.20")
SE5 4-Bladed Tractor For 200 HP Hispano Suiza Engine (Gear Ratio 35:59)
Drawing No. T28097 Issue 2, Dated 8 Jun 1917
46.5 " radius (7' 9" diameter + or - 0.20")
What you see above is Propeller dia's for the 3 main setups of the SE5A. they depend on engine, and reduction gear.