This drawing was auctioned yesterday. (Heritage Auctions)
Fetched $836.50 (Incl. BP).
Now, it doesn't look like Barks of 1982 vintage at all to me.
Never seen a Barks sketch that looked like this. Even the signature is off.
I'd have to say fake, when it comes to this piece.
Bonus:
The drawing below was withdrawn from the August - September ComicConnect auction. A rather crude fake. Happy it was pulled.