Go to Lowe's or Home Depot.
Go to the plumbing section and they will have a drawer / bin full of all sizes.
You may be able to find a thin Teflon or brass washer that will do the trick.
Just a thought!
Yeah I know that feeling!Oh yea, they should have what I'm looking for!
I should buy stock in HD now. After buying the house it seems we can't not spend money there every week