Seat back o-rings again

I am redoing the seats on my series 2 and bought an 40 o-ring kit from the usuals. I figured after 40 years it was time to replace the o-rings. The new ones are much smaller in cross section and actually longer than the old ones. WTF! So, I put on my engineer cap and start researching on the internet. I estimate the original ones when new (and not stretched out) were 5/16" in cross section and 2" ID. EPDM rubber is a good weather resistant choice. A metric 8mm cross section o-ring will also work.
I have requested a quote from 1 vendor for 8x54mm EPDM o-rings. I will let you know what I find out. Does anyone have a source for the correct rings?

Here are some from one of the usual providers of Jag Etype spare parts.
https://xks.com/i-7152853-jaguar-e-type-seatback-o-ring-set-39-3514.html

Here is one from the UK
https://www.lakewell.com/en/jaguar/e-type/s1-61-68/fhc/backrest-frame-rebuild-kit-2-front-seats-jaguar-xke-4-2
Here is another from the USA
https://shop.bassettsinc.com/40-pc-Seatback-O-Ring-Set-XKE-42-Series-1-2-3-SEATBACK-O-RING.htm

Thanks for the links. I am in the USA. The XKS has no dimensions, I can’t call them because of covid-19… the bassetts at least have a ruler in the photo so I can scale and measure. They also seem larger that the old ones. I may just keep the old ones, but will keep searching.

That proves that little to no effort goes into research for the correct parts. O-rings come in nearly every size and the correct ones are available from kit suppliers in the know. Not even the effort to buy a bag to measure them.