Fine Points.(The Talk of the Town)(Jerry Douglas' visit on a vintage-guitar store )

Devotees of "Antiques Roadshow," which, if nothing else, has exposed the financial folly of refinishing old furniture, know that a backstory adds value to any old thing: "Because it's a matter of public record that your grandfather did time in the Hannibal jail for stealing this hutch from a barber who once trimmed Samuel Clemens's mustache, it's worth a lot more." Brrrrinng! So one wonders what the 1980 Martin M-42 custom guitar in the display case at Matt Umanov's vintage-guitar store, on Bleecker Street, would fetch if it didn't have a knife gash in it from a bar fight in Mexico, and if the scary-looking metal folding knife that allegedly caused the gash didn't come with it. Guitarists believe some guitars have a strong mojo. "In this case, we're offering the mojo itself with the instrument," Danny Reisbick, the store manager, said the other day. The asking price for the wounded guitar, with knife: $6,995. Umanov recently sold a steel resonator guitar that is accompanied by a gentler but no less colorful mojo item: a mud-dauber wasp's nest inside its body. Price with the nest: Brrrrinng! $3,495.

So much to know! The visit of Jerry Douglas, the Dobro player for Alison Krauss and Union Station, to the Umanov store a couple of weeks ago--the day of the group's appearance at the Beacon Theatre--proved to be an impressive reminder of how refined fine points can be. Douglas, who was looking for a Keeley overdrive pedal, noticed almost immediately that the store had, besides the lacerated Martin and the mud-dauber resonator, two guitars made from koa wood, which comes from Hawaii. He saw them from afar. Hawaiian-style guitars are slide guitars, played on the lap, like Dobros.

"Oh, that one was made from a tree on the west side of the island, and the other one was made from a tree on the east side," Douglas, a stately man of some fifty years with brown, thatchy hair, said. "You see how the grain on that one, from the east, is pretty straight--lots of rainfall there. But the grain on that one is ...