It's probably just another document that fell out of classification and was published in accordance with blanket sunshine laws. A) This sort of thing is probab

It's probably just another document that fell out of classification and was published in accordance with blanket sunshine laws. A) This sort of thing is probably not a great handbook in the first place; it looks like a committee just decided to compile a bunch of general knowledge about sabotage in a big bullet-point list. B) Information from the 1940s is probably not terribly relevant today. It ignores modern safety systems, engineering principles, surveillance technologies, and most kinds of telecommunications. Any prospective saboteur trying to put this 'manual' to practical use will probably get caught or maybe electrocuted in short order.