I know those books. My Grandfather had them several years ago. He enjoyed them because it reminded him of his youth and he had done most of the thing highlighted in the books in one form or the other.
When he passed I was able to get them. I've only got a couple, I know there were several in the set. The two that I have are FULL of great information. I'd bet if a person looked they could find the rest of the set at second hand book store or thrift type stores......I really should do that.
IIRC they started as a class project for young students and developed into the series of books.