Looks like the Mantle is in the upcoming SCP auction.
http://catalog.scpauctions.com/1952_...-LOT52543.aspx
SCP is estimating that it will sell for $1.5 million or more. If so, not a bad ROI seeing that is sold for $705K in Heritage less than 3 months ago.
A question for the lawyers. Does the auction house have any sort of obligation to disclose that the card was recently in a PSA 7.5 holder?