"This pencil on photo blue card stock of the WOLVERINE and the signature of JOHN BYRNE has been inspected and declared true and genuine by Scott L. Ferguson executive director, Art Encounter Fine Art Gallery of Las Vegas NV. Art Encounter, a highly respected third party appraisal service is the same professional appraisal service used by the television show PAWN STARS on the History Channel. You will receive this independent third party appraisal with your purchase."

I call fake on first glance.  I'm not an expert but my gut instinct doubts it's validity.

Secondly, when does JB ever have a tiny figure on a big page?  This doesn't look like an aborted group shot or anything along those lines to me to justify such a layout.

EDIT:  I'm sure other JB fans will notice once they see this thread but the line weight and lack of variation was bugging me too.  It's obvious when compared and I thought the pencils were a little too polished too.  This "feels" like a vintage era drawing but my recollection is that JB dated most(all?) of his sketches back then and would especially have on a non sketchbook type of thing like this(IMO).

...okay, just did a little Googling and the original appears to be from '76 and in someone's CAF gallery already:

https://www.comicartfans.com/gallerypiece.asp?piece=885204

So, is this eBayer lying about Scott L. Ferguson's stamp of approval too or is he just bad at his job?

They don't seem too clear on that themselves:

I don't ever recall seeing JB draw on Blue Line Pro... did the company even exist during this time of JB's career?