Montrose was then part of the Edgar Winter Group, and claims he had his rare 1959 'burst stolen from a EWG show on 20 October 1972 in Dudley, Massachusetts.
Montrose says he bought the guitar from J Geils in 1972, and used it to record the Edgar Winter Group album They Only Come Out at Night.
Montrose says he has since hired private detectives over the past 37 years to track down the guitar, but he had no luck.
Until he saw Gary Moore's guitar collection in the British guitar magazine, Guitar Buyer.
Montrose is convinced that one of Moore's pictured Les Pauls is his missing guitar.
According to court reports, Moore has not responded to Montrose's efforts to establish contact since 2007, so Montrose is suing the Irish rocker. There is no suggestion Moore was behind any claimed theft in 1972.
Reached at his home in Brighton, England, Moore refused to discuss the matter, saying only that the “whole thing is a sham” and “I’ve had that guitar for more than 20 years.” Montrose doesn’t dispute that notion, but he insists that doesn’t change the fact that Moore is in possession of his stolen guitar and must return it. An angry Moore refused to comment further on his tussle with Montrose over the decades-old instrument.