Being as these originally came with a non-adjustable nut, it might still be an Alembic nut, but the owner wanted to keep the instrument historically accurate. I asked Alembic about putting an adjustable nut on my '76 Series I guitar while it was in for a tune up. They suggested since it was working fine, I should just leave well enough alone. Suffice to say I took their advice.
The gig bag with this one is cool.
Bill, tgo