wow I have never seen one. you can use a 26.2mm post without a shim. 0.1mm is not a big deal. I often find bikes with 26.8mm posts from the early 80s where there should be a 27.2mm I think there was a shortage during the transition period when most high end bike became 27.2 and there were all kind of leftover 26.8s or something.
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1 Super Record bike, 1 Nuovo Record bike, 1 Pista, 1 Road, 1 Cyclocross/Allrounder, 1 MTB, 1 Touring, 1 Fixed gear