I have a pre-serial number stamped 20" Formula 602 that weighs 2495 grams (medium-heavy). There is no key-holing or warping cymbal is perfectly flat. I have owned the cymbal for 30+ years. It cleans up pretty good! Very slight cracking at the hole. I'm not sure what it's worth I have seen $300 to $800 for similar cymbals so I'll ask $600 negotiable