JW06 Peril of the Black Forest

All of Western's comic books had an area where they placed the so-called Indicia, i.e. technical facts about the issue, the publisher, the printer, and so on. In most of the books the indicia was placed at the bottom of page 3, which was where Barks had his first page of a 10-pager Donald Duck or a longer adventure story starring Scrooge. Barks knew this and, consequently, his start pages were always 3 rows high instead of the normal 4 rows leaving ample space for the indicia.
But sometimes Western would place the indicia on page 2 (the front cover's inner page). Here you would typically find a one-pager, and this presented a slight problem, because Barks usually drew his one-pagers in 4 rows. Quite understandable, because he would never know in beforehand where a certain page would show up in a particular comic book. So when Western occasionally decided to place a Barks one-pager on page 2 along with their indicia, they had to disfigure his story start page art slightly.
The graphic example presented above is from one of Barks' latest stories (which was later inked by Western artist John Carey), and shows that Barks was fully aware of the indicia problem, but Western did not place their indicia in the usual place after all. Instead they placed the story's logo and title in an open area on the top of the page.

U$33 Tree Trick

Barks had experienced some of his one-pagers being cut by one panel, i.e. consisting of 7 panels instead of 8, to leave room for Dell's Pledge for Parents on the front cover's inner page that was placed in all of the comic books. So Barks thought it would be a good idea to draw only 7 panels for this one-pager - but he miscalculated: Western did not use the extra space. Instead they stretched the artwork so that it filled the standard two bottom panels...

WDC042 Kite Weather

Barks drew this story as a normal 10-pager but with only 6 panels to a page, but Western changed the format into a 7-pager with the normal 8 panels to each page. The observant - and mathematically inclined - reader might want to know what happened to the missing 4 panels (from 60 to 56) following that action, but Western simply stretched the existing panels to fit the new format.
It is unlikely that Barks knew of this major operation in advance, because if he was, he would most certainly have been asked to perform the alterations himself. This would probably also have meant a few changes in the panel flow, as Barks always made sure that every page ended with a so-called cliffhanger, i.e. a panel that leads the reader curious to the next page. Western's action shattered this special continuity.

WDCS063 'The Lost Dollar Bill'

In the story's last panel Western provided the ducks with haloes, apparently to underline that the Ducks were returning home after having performed a good and unselfish deed. This way every young reader would be sure to get the message. The halo panel is taken from the Danish first edition, while Barks' original panel is shown to the right.

U$33 Bongo on the Congo

Barks mistakenly gave Donald a pince-nez, like the one Scrooge is normally wearing on his beak. This was corrected in later issues. The faulty panel shown here has been taken from the Danish first edition.

U$16 Back to Long Ago!

Barks drew the leftmost panel - complete with expressive dotted lines - indicating that the two ducks were suspiciously eyeballing each other. Strangely (because the whole visual gag falls to the ground) Western decided to erase the lines, and they did not even bother to add bricks to the wall as 'compensation'! To make matters even stranger Western left the corresponding dotted lines two panels later!
The leftmost panel was never published in the USA (the example has been taken from the South American first edition), and in the edited panel - which is the one known today - you will be able to see a few dot remnants if you look closely...

FC0108 The Firebug

Barks' story ended when Donald was jailed for burning the courthouse down to the ground. But as it was not considered proper to show a classic Disney character behind bars following a crime, the last two panels were redrawn by Western thus achieving a much weaker and uninteresting ending, in which Donald was supposed to have dreamt everything.
One more time Western enforced an alternate ending in Barks' stories, but in this instant he was informed of Western's decision and had the opportunity to - very reluctantly - make the alteration. It happened in HDL17 Be Leery of Lake Eerie (see more HERE, last paragraph).