This is a book my 84 year old grandma talks about reading as a little girl, in the 4th grade– it would be so special to find it for her! She believes it was a golden book, circa 1940. The book features a man with a red and black plaid shirt that stole a little boys dog. The man denied stealing the dog, but eventually the dog got away from the mean man and made it back home. When he got home, he had a piece of the man’s red and black plaid shirt still caught in his tooth. The little boy and his father then had proof in the piece of cloth and confronted the mean man. Sorry I don’t have more details for you! Let me know if there is more I can do to aid in your search and I will ask my grandmother for further details.
Thanks again for your time and consideration.