Could not find an image online, but I now located my own copy of an old VAR catalog. Here is a scan showing the VAR #424 "Monte-chaines" or Chain Holder tool which I had mentioned previously in this thread. In this case, the tips are spread with spring tension and spacing is fixed by the sliding collar.
http://farm4.static.flickr.com/
My thought was the tool on eBay France might serve a similar function as a "third hand" tool for holding a chain.
Auction image: http://www.lesolex.com/
Auction page: http://tinyurl.com/
It may be that the tool is set for a fixed spacing or perhaps with nuts for adjustment of the gap - unseen, on the opposite side of the two pins.
Of course, I may just have an overactive imagination :-)
BOB HANSON, ALBUQUERQUE, NEW MEXICO, USA