I've asked about the O-rings at the dealer, because I have a set without the little clips that hold them on. So I know you can't buy the clips separately but you can get new O-rings with the clips on them for $40 each from the dealer.
I think I may have one out in the garage with a gasket and some clips. I'll take a look next time I'm out there but may not have a chance until after the holiday.