Funny how one component or setup parameter can completely throw off a strat's tone.
So the magic is back - keeping the 59's and abraxas on board in this one. The offender was the Callaham steel block.
After replacing the prior maple neck with the rw/maple fender neck I threw the Callaham unit on. Much to my chagrin, what was a lucious and deep vintage tone, full of sparkle and pop turned into a cold, hard, and sterile sound. I thought it was the Fender neck, but I was so wrong. It literally sounded like I imagined an alumicaster would sound.
I also have the bridge on 3 springs instead of 4 and the tail is floating about 1/8" from the deck. The guitar is just lovely. Cannot overemphasize the tone of the 59's. Really just amazed - even despite running 63's for a couple years. The veneers are sweet, as well, just a bit rounder and less sparkle and bite.
In the end, I think a strat sounds best with less than perfect parts. The Callaham bridge is technically perfect, but it really imparts such a clinically cold tone to this particular guitar.