I've been giving away my 596 tubes. I don't use them much anymore. But they do look cool. I also like the sound and look of the GZ37 but since I am usually listening to music and not my amp, I prefer the old standby 5U4GB like the Tung-Sol.
Ultra-, keep the 596 and sell it in 20 years and use the profits to finance your future child's college education ;)
ill take one if ur still giving away