I'll take a look Roy but pretty sure i don't actually have that size. The 0.8 thickness is a bit odd. I found 8 x 1 in Nitrile (Sh70)
https://www.polymax.co.uk/o-rings/rubber-nbr-oring/
I did find these though
https://www.polymax.co.uk/o-ring-7-9...nitrile-70-sha