1950's OMC prop compatibilities?

[ShoestringMariner]

Does anyone know if Johnson 10hp props are interchangeable between 1954 (QD15) and 1958 (QD19)?
They look the same but I know these motors are quite different from each other
thanks in advance

 

[F_R]

Not interchangeable. Change happened with the 1958 models

 

[ShoestringMariner]

ah bummer, thanks