I've been thinking of trying this purely out of curiosity. I know the Rebel Yell is basically an exact "old" JB clone. Whereas the Holy Diver is an improved "new" JB.
Now the first JB had an Alnico II magnet, but they eventually added Alnico V magnets. I'm curious into trying the Alnico II for this reason. Plus I wanted a pickup that had the sort of lead tone as the Duncan Custom Custom, but hopefully improved.
that's a misconception
the rebel yell has completely different specs from both "old JB" and holy diver
different magnet sizes, wire gauge and wire insulation
only technical similarity with the old JB is that SOME old JBs have lower DC reading (around 13k-14k), but that means nothing considering they have different wire gauges (and some old JBs reached up to 17k, anyway)
the holy diver was indeed based on the modern JB, but tweaked for a less honky and compressed sound
never heard about the older JB having A2, but according to some guys on duncan forum, you might be right
perhaps the abraxas would be similar enough