Some of Marin’s most renowned guitar gurus have set up shop at the California World Guitar Show at the Marin Center Exhibit Hall this weekend.

Tiburon guitar maker and dealer Eric Schoenberg has a prime space among the 40 dealers at the biannual Marin show.

In the forest of 30,000 guitars on display in the hall, Schoenberg brought a rare and valuable acoustic — a 1936 Martin 000 18-S — that stands out among the others as a genuine piece of Marin rock history.

The Grateful Dead’s Jerry Garcia used it to play “Mountains of the Moon” on TV’s “Playboy After Dark” in January 1969. According to its official provenance, it was also the guitar he and lyricist Robert Hunter used to write songs for 1070’s “Workingman’s Dead,” one of the band’s classic albums.

Garcia later gave the guitar to Hunter, who created a distinctive design with a ballpoint pen on a curve in the body of the old instrument, asking price $125,000.

“For a collector, story is everything, and that guitar really has a story,” said collector David McCarthy of Tiburon. “It almost certainly was used to record (the Grateful Dead album) ‘Aoxomoxoa.’ For my money, that’s the most interesting period for the Grateful Dead, ’68 to ’70. I really like that guitar a lot.”

Schoenberg’s booths are also showing vintage arch tops and electric guitars from Mill Valley guitar dealer Bob Danielson and San Anselmo’s Larry Cragg, a longtime member of Neil Young’s band who also serves as Young’s guitar and gear tech and runs a Marin-based vintage instrument rental company.

“People pay money to see guitars, so we show the nicest stuff we have,” Danielson said. “We really try to make it a show.”

The show continues from 10 a.m. to 4 p.m. Sunday.