The headset looks like a Stronglight V4 model. It is probably original to the bike, and looks ok.
Looking at it again, I was wrong, but I still think that they might have taken the width of the hanger off of the steerer. Or maybe it had a RH stem with integrated hanger.
This is not a randonneur, so probably not top dollar. But it would look pretty nice built up as original, or at least suitable substitutes. RH used other companies components on bikes like this all the time. So there are ways to build it up without having the RH components.