Thanks to all who have responded to my inquiry. I'm a very casual follower of this list, and I really appreciate learning about the archives--should have looked there first. Having read most of the archive references from the Spring of 1996, I'll only add that a couple of additional pieces of information are included in the latest "Acoustic Guitar" magazine piece. First, they claim the provenance has been authenticated by an address label or some such that has existed with the guitar's case--I think this has Twain's handwriting and signature. Second, someone has done the appropriate Martin research, because the model number and the date of manufacture have been determined--it apparently has been verified as a Martin guitar made in 1835 by C.F. Martin. The article is very short, but it also describes the original case, which is the "casket" type (these really look like little caskets of the same period) that would be correct for that vintage. Someone mentioned back in `96 that the guitar looked "pretty beat up," but I must say that, given the vintage and the fact that Twain evidently dragged it all over creation, I think it looks spectacular. I think you all would enjoy seeing the nice picture. Best, Tim