I wish we could get everyone in a room and discuss this and share information(I'm the one who didn't go to ISB!) But maybe our TalkBass people will be able to help everyone become better educated on this issue. Here's my general view on bass identification: most makers in the past either did not make basses or they made very few. I'm leaving out the factory stuff for now. I'm talking about the purported Rogeri's, Amati's, Guarneri's and other important makers. If any of these makers made say ten basses in their lifetimes, and these basses have scattered all over the world,and some of them have not survived, then the chance of any one of us seeing more than one of these is practically nil. This makes the identification and therefore the authentification of old basses, I should say old and exceeding valuable basses almost impossible. Here's an example. A player in the Minnesota Symphony owns a bass by J.B. Rogeri, bearing an original Rogeri label and ascribed to the year 1690, making it one of the first true double basses. I know another player who purchased a bass in New York attributed to Rogeri. These basses bear almost no resemblance except for one interesting detail. Each has a wavy piece of slab spruce in the same place in multiple piece tops. The first Rogeri by the way does not in anyway resemble several Rogeri violins I have seen, leading me to believe that it may have been made by an assistant? But in this case about the only way to compare the two basses would be to view them together(or have a photographic memory). I have on occassion visited symphony orchestras where the bass section has shown me their old basses which are usually said to be Italian. To me about half are usually very suspect as to their origin. This is an important issue to all of us, because the value of basses has been going through the roof the last ten years, and I don't think there is any end in sight. I am concerned about the supply/demand side of basses especially Italian, and the effect this has on the attribution of basses and their value. About ten years ago a symphony player showed me his Gasparo da Salo 4/4 bass and it's papers provided by a well know London dealer authenticating the bass as a da Salo from 1690. I thought the bass, though a very good one, was probably English and about one hundred years newer. Not long ago I had a phone call from the dealer about another matter. I mentioned the "da Salo" to him and that I had seen his papers on it. His reply was that "of course it wasn't a da Salo". Over the years I have taken a much more conservative approach to bass identification, probably a result of having reached a level where I realize just how small my knowledge bass really is,and how important it is to be sure to pass along meaningful evaluations, and not cloud the picture with an appraisal that might turn out to be wrong and therefore wrongly influence others judgment. Perhaps here we can share some of our observations and questions.