W108 1967 M108.920 Exhaust Flange Gasket

[karshack]

Need some help figuring out exactly what kind of gasket this is. Is it a donut gasket, or an o-ring like gasket?

Both of my flanges are leaking air. I have not taken them apart because I think I may have to destroy the old bolts to save the patient. So, I need to get all of my ducks, and equipment, in hand before any surgery

I have not seen one of these on the Pelican Parts site. The Mercedes Parts Catalog "A" (1965) 12_110, [page 130), shows a donut looking gasket. But, using ebay, I get o-ring like gaskets in my search results. I can not imagine this connection is made so that one could use either shaped gasket.

Here is a pic from the Mercedes catalog, and a photo of my exhaust flanges.

engine: 1967 250S M108.920

Thanks in advance

ps: Yet another step in eradicating gas smells while driving, and after parking in the garage.