Supposing I took a drawing by Jack Kirby and I traced it onto another piece of paper and inked it on that paper and signed "Kirby and Evanier" to it. Would this be original Jack Kirby artwork? Never mind that it would not be very good. Let's just deal with what it is. Would it be original Jack Kirby artwork?
Of course not. I could no more create original Jack Kirby artwork than I could create a new Van Gogh…even if I signed it "Van Gogh & Evanier." Only one human being was ever able to create original Jack Kirby artwork…and he died in 1994.
(Well, to be technically accurate, there have been other human beings named Jack Kirby and if one of them drew, I suppose he could have created original Jack Kirby artwork. But I'm talking about artwork by the guy who co-created Captain America, The Hulk and The X-Men. That Jack Kirby.)
One of the prominent/frequent artists who inked that Jack's pencil art, Mike Royer, often does re-creations of old Kirby art on commission. He will trace an old cover or drawing of Jack's and ink it…and he'll sign it "Kirby and Royer." Mike, however, is always scrupulous about adding the date and some little line like "re-creation" so that no present or future buyer of the art will wrongly think they're purchasing a piece of paper on which Jack "King" Kirby drew.
Some other folks aren't as scrupulous. Keep this in mind if you're ever purchasing Jack Kirby artwork, especially on eBay lately. eBay, by the way, is a great place to shop if you want to pay thousands of dollars for a "certified and authenticated Charles Schulz sketch" that looks like it was done by a nine-year-old with a busted Crayola. Not long ago, you could have even purchased an original, certified and guaranteed Charles Schultz sketch done during the period when the creator of Peanuts forgot how to spell his own last name.