We are trying to get the instrument from the loft....

The muso is a bit casual and tends to refer to his Sigma that I have on loan a the moment as a Martin, so we'll see what we find.

I remember "Walk Right In". Was it played on a conventionally tuned 12? As far as my ears take me back, I would have guessed possibly a tuning lower than E and maybe even unison courses on the lower strings not octave pairs.