The origin of the story:
In 1959 Carl Barks had begun a Gyro Gearloose-story, but never finished it because it included crowds of rats and children and he didn't want to draw them. But 30 years later Bruce Hamilton sent to Don Rosa the three pencil-pages that Barks had done before he desided not to finish it. Don inked the pages and started to think a good ending for it, because even Barks himself didn't remember how would've it ended. So, Don wrote a conclusion that involved crowds of rats (not untill later he found out that it would've had also included crowds of children). But Don never finished the story for Gladstone, because before he got it ready Disney told Gladstone not to return his art and he quit. But, as you can see by the code, he did finish it for Dutch Oberon.

Thanks for getting this infromation to Simon René Magnussen