Fair price for 515-8G ?

I can say, often products were available before they appeared in catalogs.

And transition models aren't uncommon. I have 808A drivers with tapered bodies.

I suspect Altec was shipping 8G before the move, stockpiled them, and shipped the stockpiled ones after the move.

Possibly as I understand it the earlier 515 G had the torn bolts on the back holding the magnet on. The later ones didn't. When I get near another Hard Drive I've got images with labels and date codes that may help.