Not since the 80´s as far as I know.
According to an interview with JP after the release of Awake, his first IIC+ was a loan from Mark Snyder during the recording of Awake. He later bought the amp and it´s been his main one ever since.
He used a boogie head in the late 80´s (as seen on the WDAD-reUnite DVD), but I don´t think it was a IIC+. He also had a Quad/295 based rack rig (also seen on that DVD and was probably used on I&W) that later morphed into his Triaxis/2:90 rig.