That card looks like it's the card you got when you ordered a shirt from Mr. Nimoy's website. The signature looks similar to the one I have. I would say it legit, what is troubling you?
____________________ "The problem, I'm told, is more than medical."
Take a look at the scan of the same card in this section under the Leonard Nimoy LLAP Card thread. This is the same RA card sold via the T-Shirt offer. The marker width is broader on the scanned card, but you may be able to judge better just by checking other eBay auctions. Nimoy has several certified cards and his autograph is fairly consistent, if not all that readable.
Posts: 10529 | Location: New York | Registered: November 20, 2007