Z, I asked the guys at Sharps Marine in Oswego, NY, some really knowledgeable people with the older Polaris skis, about reeds, and they told me "save your money" and buy stock Polaris reeds. Although they ain't cheap, at $15 each... Ronnie and Ritchie think they're the best all-around reed for the older 650's.
Sharp's Marine were the people who finally figured out what was wrong with my triple that wanted to be a twin!