Hello!
What about Leatherman's 25-year warranty? As far as I know, it's still valid in the US.

Just tell them the tool is a keepsake and you only need the washers; I think you'll get them for free.
Seriously, finding these washers isn't hard, even in Russia. Take some from a disassembled tool from ebay, order from AliExpress, or make new ones yourself.

P.S. Once you get the new ones, don't forget to polish them with diamond paste. I recently disassembled a skeletool, and the washers were terrible!