I have the first appearance of Gyro in an issue of WALT DISNEY'S COMICS AND STORIES (#140) which is supposed to be rare, but which has to be one of the single most common Golden Age comics of which I know. Study Ebay or the stocks of any decent comic dealer at the next convention you attend and you will likely find many copies of that book. I assume that the feedback must have been positive, because Barks returned to Gearloose again and again, finally culminating in his own tryout books in Dell's FOUR COLOR title. Alas, sales must not have been quite good enough, because after a few issues (at least three in that tryout format), he was not awarded his own continuing free-standing title.
He was also never used in the cartoons of that era. I've heard it said that this was likely because the Disney animators instead went with Ludwig Von Drake to stand in as the miraculous inventor within the Disney cartoon universe. There just wasn't room for two such characters in the Disney toons.
One thing that I got a kick from when I was a kid was Gyro's assistant, "Helper". This was a little metal robot about the size of a human hand (or a cartoon duck's hand). He moved about almost as a little stick-figure person, the gimmick being that his head was an a-ha moment light bulb. Barks was no dummy when it came to being uniquely clever. Gyro would often get himself into trouble with his inventions, and just as often his little helper would find a way to get him out of a jam. A faithful friend. Every kid likes the idea of a faithful friend.
|Four Color #1047.|
|Four Color #1095.|
|Four Color #1267.|
|My copy of the supposedly rare (but not actually rare at all) WALT DISNEY'S COMICS & STORIES #140, featuring the first appearance of Gyro Gearloose, Duckburg's greatest inventor.|