With all the shiny bits sparkly, it does look like it has been refurbished and refinished. As well as the nut, the tailpeice is also a more modern version that you would expect from a1976 bass. I would also expect if it's been back for a refurb at alembic there is a good chance it has the noise cancelling system upgrade. If you are unaware of that, it's worth knowing that some of the older series basses can pick up modern electronic interference that wasn't around back in the 70's and if you can't cancel it out using the humcancelling procedure you might need that done back at base.
