No - it won't be an official Futera signature card - I've been collecting this set for 20 years (still don't have it all

and I've never seen it mentioned.
I messaged the seller yesterday and he hasn't responded yet to my query of whether he has any more info on the origin of the card, how he knows that there were 10 of them etc etc.....
Some enterprising soul may have acquired 10 of the numbered ones, bought an Authentic Autograph embosser, got them signed by Lara and ..... there you go.
I guess it could be possible that a Futera employee, when the end was nigh, snuck 10 numbered Lara's out the back door and then got them embossed and signed etc apparently some weird and wonderful things happened near the end of Futera.
The Lara 375 card had the three types- - unnumbered, numbered and SAMPLE. They weren't included in the Decider packs.
The official Futera book doesn't include a lot of of the variations contained in The Decider set including that there were definitely more than 13 of the SAMPLE Lara cards in circulation. No one knows for sure how many made it out the back door - I had 6 at one stage years ago.
Cheers
John