Looks slam-dunk real to me. Let's see what the big guys say.
Bear in mind that 3x5 cards are typically the tool of the freebie through the mail collector. And Mantle rarely, if ever, responded through the mail.
And when he was doing card shows charging high rates (for the time), what are the odds someone was going to pay the high fee for a signed index card? Almost nil.
In person is always a possibility, of course. But if you were playing the odds, the fact that it is on a 3x5 card in and of itself, tells you authenticity is unlikely.
In my opinion of course. :-)
You learn something new everyday. Thank you, Steve Z.
I'll be honest with you. It's not the worst forgery I've ever seen. If that's what it is. Just my opinion.
My first thought was that it is machine signed. It is slow and just looks off.
You may be right, BC. We haven't identified new machine-signed Mantles besides the million or so from Tony Podsada.