Thanks to OP Woogie for the comprehensive write-up. An excellent tutorial.
The part has increased to $130 shipped, but I'm surprised and happy Pioneer still stocks the part. Woogie's part number worked perfectly for my '99 ES.
One tip: don't forget to peel off the clear protective adhesive Pioneer puts on the display window. If I hadn't noticed a small air bubble, I might have left it on. Disassembling the radio gave me a good chance to check out the "innards". I was specifically looking for bulging or distorted capacitors; happily, I found none.
One other note: when pulling off the plastic front radio cover, pull straight out. There are two electrical connections being disconnected at the bottom of the front panel. It might fight you a small bit.
If you have burned out LEDs in the temp panel below the radio, this is a great time to disassemble that panel and replace them. very simple twist in and out. Mine are fine, but I still twisted them in and out a few times for a good electrical cleaning.
Thanks again, Woogie!