I suppose you know these are 92mmx2mm & 79mmx2.6mm O-rings.
They seem to be NLA and out of stock from the usual sources.
Unfortunately, metric O-rings come in a million sizes. There are around 450 "common" USA O-ring sizes - they were standardized for WW2 military production - 99% of inch size O-rings used will be one of those... and all are usually available readily from bearing or seal suppliers.
For metric you have a lot more trouble, there's no "standard set". No supplier is going to stock the countless possible sizes. Any size can be custom ordered but you must buy a hefty minimum order. Not much use for the 999 extra when you only need one and have to buy 1000.
You can make your own... 2.6mm is an odd size but 7/64 O-ring material will probably be close enough at 2.8mm? 2mm is very close to 5/64 (1.98mm). You just have to get O-ring cord, cut to length, and superglue the ends together. You can get kits but I'm unsure of how common 7/64 and 5/64 cord is.
