MSH 50135 washers. Where the heck do you find them?

I can't seem to find these washers. They are used in the main grips and in the tail shaft. Looking at the pictures on MSH's website I can't seem to find them separately, with the grips or in the tail shaft / assembly. Where the heck can I get four of these? A used Protos I just bought is missing two in the tail and only has one bent up one in the head.

Thanks for your help.

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