@isaacc7 @jackd I am in Denver and have a great tech nearby. If/when I improve my preamp game, I'll consult with him about older models. I know he really likes deHavilland. I am saving this thread into my "end game folder" and now really have a star next to Supratek and Aric. And Don Sachs.
I hope to borrow a deHavilland Ultraverve III to compare with my Quicksilver to see what differences I hear. I realize that the rest of my system and room needs to be revealing enough, so I won't prejudge too much if I don't hear a large difference.