This is not a big issue but it may help someone. I am a retired mechanic of 40 plus years and I could not believe I almost missed this... My 63 CDV had a leak at the flywheel O-ring. In preparation for the repair I read many online stories about the O-ring missing completely when they removed the flywheel from the tourrus on the Jetaway transmission.
I removed the trans last week and pulled the flywheel off. Upon inspection I thought "wow, the O-ring is missing off my flywheel too ! " I cleaned the flywheel and scraped the area where the o-ring should go with a scraper. It all looked like clean metal so I installed the new o-ring on the flywheel and assembled the flywheel back on the tourrus and tightened it to specs. The whole time I kept thinking, " something does not seem right ."
After a nights sleep I went back out and pulled the flywheel back off. This time I really scraped the surface where the old O-ring should be and what do you know, the old O-ring presented its self ! It had looked just like the metal on the flywheel ! The old ring was hard as a rock.
This may make some of you think, "what a dummy" for not catching this the first time but believe me, it looked like part of the flywheel ,,,so beware !