I agree that 1988 pricing was probably 15% lower than the 1990 peak and that is supported by sales records.

“I figured 1988 was near the top, then figured another 15% or so for the actual top in 1989/1990, then figured it was reached again around 2000”

It almost sounds like you are suggesting that the nominal top of the prior 1990 peak would have also been the nominal top of the current cycle around 2000-2001 had it not been for the credit bubble which extended the cycle for an additional 7 years. Why should the top of this cycle (which should have ended in 2000-2001 as you suggest) have been nominally the same as the top of the prior cycle in 1990?