Will An O-Ring Work for Gas Side of Challenger V

I got two used kegs and went to clean them out. I found they have plastic gas dip tubes which I found another post on where to get replacements for those. However, both the liquid and gas dip tubes have what looks like a washer instead of an o-ring. I read a couple posts about a white washer which I don't believe my kegs have.

I read several posts which were helpful but I could not find anything on the washers. Being the idiot I am, I threw them in the garbage figuring I could buy new ones. I have been to williams, chi, NB, Midwest, AHS. I found the plastic gas tubes but not the washers. Can I use a normal o-ring? Do I need the white plastic spacer?

Thanks

I've got a similar keg and just using the normal o-rings works for me.

Thanks. I am running low on co2 otherwise I would have tested it. I am not a fan of these kegs. Now I know.