Hi Dom. I had one too. First I just thought it was some dirt but it seems to be a rubber ring, mine unfourtanetly was torn up, but still in one piece... So it will not function properly I think. But yes there was one, but it was not firm as on the schematics. made of soft rubber. regarding the bellevilles I just had to put them the way they would give me a slower drag curve. It was mounted like () but they were deformed so the best option was )(. I still have to have new ones. No doubt it is a beautiful reel
Note that by orienting the belvilles like )( may damage the star clicker assembly (bend it) and may also damage the handle bearing as the beleville will rest on the shield during compression.