Vintage Double Hose

On the trademark USD horseshoe which holds the the black disc seat there appears to be a rubber (possibly and old oring) on the stem in between the seat and the back of the seat holder. Wish I could picture this one to you all. A. Is this an oring, B. Is it just verdigree, C. If an oring is it replacable? D. How the heck do you replace it.
I originally thought it to be dirt and goo but now have found it to be an old oring or some type of a rubber spacer for the seat mechanism to buffer itself on? Any suggestions or is there a manual from Bryan I can get.

I'm confused? Why don't you post a photo and I'm sure one of us will know.

It is a rubber spacer. The seat is free to swivel to align with the nozzel. I really don't believe it is necessary. I removed one but could could not find any difference in operation but I cut a small O ring so I could slip it around the stud. I wouldn't worry about it too much.

Captain, I just did exactly what you did. Cut one oring and put it in place. Waht I was n't sure about was the operation. You answered that. Thanks for the info. Bryan I will post phot later today. Going diving.