Can someone tell me what size O-ring is used for the pivot?

I got the fancy gasket from the dealer, and figured while I was in there I would replace this O-ring. I think I've got an old dash bracket to make a stop for the pin on the outside. I will also finally get around to replacing the kickdown shaft seal. I spent weeks looking for one. Just happened to be in NAPA one day asked about it. $1.50 on the shelf. Guy on the phone told me part number on their website was no good. No one else even had a clue. Found a guy on ebay selling them for $15 + shipping. The kickdown seal didn't appear to be bad or leaking, but I did replace the shift shaft seal, and figured that one needed replaced too.