IIRC Bensen examined the FA330 in depth before getting involved with evaluation of Hafner's Rotachute/Rotabuggy.
Again, IIRC, Ken Wallis modified a B7M , a Bensen autogiro (not a gyroglider).
Without in any way detracting from Ken's huge contribution and engineering acumen , I think perhaps there is room for some acknowledgement to be made to the pool of expertise that he had access to at Boscombe Down in the late 1950's.