The counterpart to the flute whimsy of Ian Anderson, Martin was a guitar wielded for Jethro Tull from 1969 to 2011. Though Martin mostly played Les Pauls, he also played flute and mandolin, and as evidenced in this photo, a black Strat. It’s a Strat plus, which Fender no longer makes.
This clip of Jethro Tull performing Roots To Branches shows Martin with the Strat plus.
Although Martin is not sure what guitar he used on Stand Up, this track sounds like a Strat through a Leslie speaker.
Martin Barre is an excellent guitarist. It is a shame that he and Ian don’t play anymore, but the Martin Barre band is very good.