In a 1991 interview with Guitar World, James noted that he recorded most of “Nothing Else Matters” on a Tom Anderson electric guitar.
Most of that song [‘Nothing Else Matters’] was played on a Tom Anderson electric guitar. We recorded it using two extremely clean signals: one through an amp and the other directly into the board. We really worked hard on that sound, and are real proud of the results.
James Hetfield, Guitar World, October 1991
However, in the music video for that song, which shows the band recording the song, James is seen using his black ESP guitar most of the time, and the Anderson guitar is nowhere to be seen. So, this was likely one of Kirk Hammet’s Tom Anderson ProAM guitars he was seen using around the “…And Justice for All” era.
Kirk is also seen using this guitar while recording part of “The Struggle Within” solo during the making of the black album doc.