I will be a great match - the Ref3 was an usual recommendation at the time, as they matched perfectly in electrical terms, and the REF5, that has better definition in the bass and more slam, will be a much better match.
I have no experience with the Salon2 and I am extrapolating from my experience with the REF3 and the FPB750 MCX - I think that the 450 MCX will sound similar.