I'm glad to have David's opinion on this chip Charles. I acquired one of these chips at the convention this year at what I recall to be low book. Same condition - seemingly brand new. Pestered about half dozen authors and gurus who pronounced the beastie to be legit as well.

Both my chip and the eBay example have symmetry of inserts to inlay but my chip has an odd little wrinkle on the fine print side.

Auction states "very rare". Really? R-4. I'd stick with the guides on this chip.