Awesome. Thank you all for your input. I will go for the full kit, hopefully from vesrah. I did search ebay, not very well I guess, and did not find any. Old Bike Barn had a full kit for $150 for the cb550.
Other question, is there a difference between K and F? I have 2 engines and they've been moved around so much I don't remember which is the original. I suppose I could check the number... but the engine in question is about 10 miles away, and my buddy wants the o rings now.
I will, after rechecking ebay, give my local dealer a shout about the vesrahs.