Yah. A few days ago when I changed my oil and filter I looked for the "small O-ring" and found it under the silver washer.
The silver washer is spring loaded against the O-ring and the only way to get to it is to disassemble the spring loaded cap.
Why anyone would ever want to do that is beyond me. That O-ring will last 30 years if it is left alone.
I'm pretty sure your gold (brass?) washer is mounted correctly in the photo.
The big O-ring between the washer and the filter sits outside the "bump" on the washer, being almost equal to the outside diameter of the gold washer.