From the photos, I get the feeling that this indeed is an Rene Herse - but it is a very unusual (and in my opinion not very desirable) one. So you may be able to get it for not too much. I'd be surprised if it attracted high (Japanese) bids. I may be wrong - maybe the rear derailleur is worth $ 4600 alone... ;)
Unusual features: - fillet-brazed, when all Herse tandems made after 1945 that I have seen were lugged, with hand-made lugs. - ladies back: never seen that before. Herse tandems are known for their stiffness (relative to other tandems of their time), so this wouldn't make much sense. However, they often built what you wanted, so if somebody ordered it, they may have consented to build it, especially at a time when orders were low (which was the case during the late 1960s) - No oversize headset, or both cups oversize (I can't tell). Herse, Singer and a few others always (as far as I know) used oversize bottom headset cups, and standard top ones. The steerer tube tapers, so it has greater wall thickness at the bottom (where lesser tandems tend to break), without incurring the weight penalty of a massive steerer tube with oversize walls throughout (as on a Jack Taylor, where the fork weighs more than most bike frames).
Once again, maybe the buyers were concerned about getting spare parts, so they may have spec'd a standard headset.
Features that make me think it is an Herse: - racks are typical Herse - dropouts - it says so on the down tube (few repaints get the lettering correct)
A few things to note: front hub spacing on these usually is 110 mm. Fortunately, the Maxi-Car tandem hub with that spacing appears to be there. Tires are not a huge problem - contact Bob Freeman on this list. Otherwise, the parts look fairly standard.
However, be ware that when the builder didn't like a bike, it sometimes shows in the workmanship. I know with Singer, if you ask for stuff that is too odd, they may do it, but they won't do it as nicely as they would a bike they like.
I think the "Made in France" lettering was done on bikes for export only, so the story of an American buyer picking this up in Paris rings true. I never have seen this on a French bike.
Coincidentally, issue 5 or 6 (depending whether the technical trials with their superlight bikes will fit in one issue or two) of Vintage Bicycle Quarterly will be dedicated to French performance tandems. Paris-Brest-Paris was won three times in a row (overall!) by Jo Routens on a tandem (1948, 1951, 1956), the last time he tied with a René Herse tandem. Those guys rode 1200 km on hilly roads in 48 hours - a record that was broken only in 1999 by a team that had a support car and numerous other amenities lacking in those days... And the mixed tandem record of 1951 (49:40 hours or so) also was broken only in 1999, and only by a few minutes. That one, too, was on a Rene Herse tandem.
Jan Heine, Seattle
Editor/publisher
Vintage Bicycle Quarterly
http://www.mindspring.com/