Ungraded Alnico is correct, the nearest modern equivelant is ALnico 3 as plain Alnico is a different product these days.Our Apaches and Country Boy pickups feature original Alnico made specially for us.
Alnico V crept in sporadically from the late '50s onwards and Fender moved from using Heavy Formvar enamelled wire, through plain enamel in the '60s to polysol in the late '60s/ early 70s.
Magnet polarity also changed, seemingly randomly.It started off north up for @ the first 3 years then moved to south up and then changed back and forth although south up does seem to predominate.
Hook up wire was the 7/30 waxed cloth hookup and then moved over to plastic coated hookup in the '70s.
