Re: Is this a 1987 PL2550?
Hmm, this is probably the fourth one I've seen with IBZ pups. I thought they were 1987, using up leftover stocks of bodies etc. with the new, redesigned pups. 1987 was a year that had all sorts of kooky combinations, some which stayed only in Japan... Though I think someone said once that the IBZ loaded ones were US only or something like that.
Yet, the one in the link is probably modded - if you look closely at the bridge pu ring, it has an extra hole drilled for the centre screw of the IBZ pup.
The stock IBZ loaded ones have bridge pu rings for 2 height screws only and the pups are black.
Jim is right about the painted vs. oiled necks, the Ibanez book is a little misleading.