that one is worth whatever you paid at the flea market -- however, if you noodle around Abebooks you might see what others are asking. Repair manuals is not, I suspect, a huge part of the camera collecting market but it might be worth $50 or so to someone who wants it.

It's essentially a repair manual for an M2, although I understand it does contain a quaint warning about destroying the camera with an axe or hand grenade if it is about to fall into enemy hands.