As I understand it, CE's went to the mahogany/maple combo in 1995.
From the PRS site:
"CLASSIC ELECTRIC (CE BOLT-ON): 1988 - Current. 24-fret maple neck, unfaced headstock, dot inlays, alder body, PRS Vintage pickups, tone control, and 3-way toggle selector. Rosewood fretboard, wide-thin neck options by ’89. Black headstock face and 5-way rotary switch by mid-’89. HFS Treble/Vintage Bass finalized by ’91. Maple top version- the CE Bolt-on Maple Top- added in ’89. Mahogany body/ back from ’95 as well as stop-tail option. Solid Mahogany body discontinued in 2000, stop tailpiece & regular neck profile discontinued in 2001. Offered as wide thin, tremolo only from 2001."
My 95 CE has a mahogany back & maple top.