Need help identifying these pcp air tank components. Please

I have a 74 cubic ft Air Venturi air tank which I suspect has a slow leak from the fill valve.
I need help to identify some parts so that I can google them and buy new orings and washers.

In the picture, there is a metal washer which has a built in rubber oring in the center. The od is .815 and id is aprox .500 as it's looks worn.
What is the name of this washer with an oring?

I think I can match the single black oring that fit at the end of the large metal screw in adapter. But if you know of a universal part number for this oring, I would appreciate it.

Thanks in advance
Rod in San Francisco

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