Banjo brake line washers

Had a leaking banjo line at the caliper. They are the rear disc conversion from Right Stuff. I tried several ways to stop it, no go. Yes, I probably over torqued the bolt, I know now. I called a friend up, he said that he had some washers that were steel with a rubber sleeve/liner that should do the trick, they did. Question is, where can I get spares? He doesn't remember where they came from. Look familiar to anyone?

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