Barks?

Maybe I should re-name this blog to "Things that puzzles me".
Here's yet another thing I found in my bookshelf today that I began to wonder about.
This is the cover to Donald Duck #46.

The cover is credited to Carl Barks and his records indeed shows an entry for that cover. But... What was printed on the cover of DD #46 was probably not the artwork that he submitted.
-What do you mean? you might wonder. -Inducks and all other indexes credits this to Barks. Then it surely must be by him.
And I reply: -Are you sure?

Looking closely there is no doubt that Carl Barks did Donald's head and the right part of the body. But the nephews and the cake are inked with a brush in a completely different style. My guess is that the art editor saw something wrong with the position of the nephews and felt he could improve the way they blew the cake away. So, said and done: he redrew part of the cover. Any qualified guess who made the new artwork?

Barks version probably had one nephew standing in front of Donald (That's why that part of his body now looks cut off.) and possibly they blew the cake towards the reader, making the action unclear.
And, thinking about it: Maybe all of the nephews stood on a straight line. That would have made a dull arrangement and a reason for the editor to make a change. To support this theory is the fact that Donalds elbow is drawn with thicker line than the rest of his body and the lack of tailfeathers on Donald! If the nephews were shown standing in a row that part of Donald's body wouldn't have been seen on Barks cover.
But that's just a guess and we'll probably never know the answer.