There is a picture of the bike currently discussed, as I found it, at the end of the following link :
http://www.reneherse.com/
I stripped it of all the more modern parts that had been added, polished it, and sold it to KD a couple of years ago in the region of 1800 USD.
Was this an interesting bike? I would say yes, because most Barras are beautifully made, and it is rare to find one with original transfers. And they do have a tendancy to develop cracks, though not to the extent that Norris indicates (BTW Caminades are not immune to failure, fork snaps). This one was good as I remember it.
On the other hand, a racing Barra has nothing like the level of workmanship and detail as a cyclotouring one does. Compare for ex with http://www.reneherse.com/
It depends of course what you are interested in, a TdF buff will find the racing Barra more interesting... But there is no doubt the cyclotouring Barra has more parts of interest and beautiful hand-built details. Most people interested in these French hand-builts are looking for just that, the hand of the builder.
Originality. The cyclotouring Barra above is as found, 100% original (bar tape, cables renewed but those are the replaceable parts). The racer has just the frame + stem original. If it was sold as a frame (unlikely), then it would have been of great interest to find it as it was built up at the time by whoever bought it. If it was sold as a complete bike (far more likely) it would be much more interesting to have the bike as Barra (and probably the buyer, these bikes were made to measure and the buyer usually chose equipement with the maker) fitted it out. If you're interested in old bikes, surely it's because they have a history, and a modernised bike has had some of it's history wiped out.
Obviously, once the bike reaches us modernised, then someone has to guess what it MIGHT have been like originally. However educated the guesswork, that will never be as good as the original.
There are cases of course where you find a bike modernised, but original period photos of the bike exist. In that case you can put the bike back exactly as it was supplied in the first place. I would say that is very nearly as good as fully original, but not 100%...
Nothing will beat a bike that is fully original and never modified. My opinion only of course. There are ayatollahs of originality as there are ayatollahs of "who cares about originality". There is room for everyone, the modded bikes can go to the second category of collectors, any 100% original and beautiful, please write to me offlist. I'll willingly exchange 5 modernised frames for one original bike.
Alexander March
Bordeaux
France