Good Day!
I'm new the the board, and have enjoyed scanning the comments. This topic I know a tiny bit about so I'll add my 2 cents.
With the first incarnation of the Orchestra, John was Les Paul->Marshall. Soon, he was Gibson SG double neck -> marshall. That lasted a long time. Soon after he met and started colaborating with Santana, Carlos discovered Mesa and turned McLaughlin on to them.
I saw the 2nd incarnation of the Orchestra when they were on the Apocalypse tour (Ponty, Walden). John was playing the playing the Rex Bogue double Rainbow through a Mesa Mark I combo, unmiked, no effects.
Best guitar sound I've ever heard. From that day on, I've wanted one of my own ...
Be well
Oscar