Steve,
this link may be of use to you:
SE.5a Walkaround | The Vintage Aviator
Its a reproduction of a late-model SE5-A with an original Hispano Suiza engine in it, and two bladed prop.
According to the TVAL website, many pilots made modifications to their aircraft, fitting a geared engine with a four-bladed prop may have been one, if it wasn't a standard engine fit.