Spin on oil filter adapters O-rings?

[Norton47]

While getting ready to re-assemble the engine, I was cleaning the spin on oil filter adapter. I noticed the main body to adapter square o ring was hardened and will need replacing.
My question is about the groove in the center of the adapter.
Is there supposed to be an o-ring there also? It looks like ti to me. Unfortunately, there isn't anything in the baggy that was holding it. I don't know if it dropped out and I missed it when I took it off, or if it was always missing or if there shouldn't be one.
The photo's in the BPNW online show a flat seal there and say MOCAL has improved the sealing. I can't find any other photo's.
Anyone got one on the bench or got one for Christmas and hasn't put it on yet?
Thanks

 

[martx-5]

I have the adaptor kit in front of me, but it's for a TR3. It definetly has a smaller O-Ring that sits inside a recess in the adaptor. It's a round section O-Ring, so it should be available at your local FLAPS. It measures about 1-5/8" OD and has a thickness of about 0.142". You're dimensions may be different, but you should be able to find something that fits your adaptor.

 

[poolboy]

Just recently put one on my 74 TR6 and agree with Art about the seal. The square O-ring is the same as the O-ring that was needed with the old cannister.
The other one surrounded the mounting bolt, though larger ID than the bolt's OD and fit in the machined flat surface of the conversion.

 

[DNK]

mark- are you talking about the big 5 inch one. Check the crevice where it seats. They usually get lost in there.