The tandem that Norris outed can be found here:
http://cgi.ebay.fr/
A measure of the interest that Follis tandems have in France is that it has over 500 hits.
As Nick Bordo stated, the Singer tandem is also back for sale:
http://cgi.ebay.fr/
The description has been changed to point out that it has René Herse cranks on it. They do state in the description that the bike is to be collected locally (in other words apparently no shipment). The tandem is quite odd in that it has both a front a rear brake on one single lever. BTW, it is the same seller as previously, so contrary to what I had thought the seller seems to be on the up and up.
Steven Maasland
Moorestown, NJ
USA