The Fox and the Hound - 1967 First Edition

This is a 1967 first edition of The Fox and the Hound by Daniel P. Mannix, winner of the Dutton Animal Book Award in the same year. The other night me and my wife went to a local auction, and I finally found it. We bought a couple other things, but the real find was a cardboard box with a bunch of different books in it, some of which over 100 years old, and I noticed that one of them tossed in like it was nothing was this 1967 first edition of The Fox and the Hound, the novel that the Disney cartoon classic from 1981 was loosely based on. This is a very hard to find book, so I can't believe they just had it tossed in with a bunch of other books with very little value. I paid $10 for the entire box of books, so I can either look at it like I paid $10 for this one great find, or average it out to a buck or less.

It is complete with the dust jacket but it's certainly not in mint condition, the dust cover is a bit rough, but the actual book itself is fine other than some staining around the edges. It really doesn't matter much either way for this one to me however. It also looks to have been a former gift for "dad" and whoever gave it as a gift cut the price off of the inside of the dust jacket and wrote "...to dad" in it but that is also fine by me. I never thought I'd be able to find it in the first place.

While I obviously know what this book is, there is still a bit of mystery surrounding it for me. I would like to know just why this one is so hard to track down in any condition at all. Was it a very limited first printing? Is it known how many are out there?