Kirby Art?

A fan sent me an email and asked me if I think this page is an authentic piece of Kirby art. Here is the website and the link.

I don’t think this is by Jack. Obviously the Cap image is from Captain America # 200.

I don’t recall Jack ever signing anything “Jack the King — Jack Kirby.”

Also, Jack tended to use a double dash, not a single long dash — I’m not sure if I ever recall Jack using a single long dash in his margin notes. Notice even the two “Jack” signatures are very different — the writing looks shaky and dips up and down. Is this an obvious Kirby forgery? Or are we looking at something here done by Jack at the end of his life when his health was failing him? Does anyone know the backstory on this? I’ll forward a link of this post to the owner of the Kirbyart website, maybe he can give us the provenance. I’ll obviously assume he thinks this page is legit and maybe he has the background concerning previous owners.

I’m certainly not accusing this website of selling a Kirby forgery, but stylistically, this page doesn’t look like Jack Kirby art to me at all, or could this be a piece done at the end of Jack’s life where Jack might have worked with an assistant? Or is this just a flat out fake piece of Kirby art? If this is a forgery, I sure hope someone doesn’t spend the asking price of $5200 on this. I’d say there is no way this was illustrated by Jack Kirby, but any new information on the history of the piece would be most welcome.