Nah, if anything the manuals are just a further watering down of rewards from league boats, victory chests and presumably expeditions. It takes an absurd amount of them to upgrade just a single wall piece, out of the 150+ that you end up with by atomic age. This is just an attempt to make the laughable addition of the archive slightly more useful. If you could purchase and stockpile them with the RSS that just piles up in later ages then they'd be useful, as is, they're even less practical than a 5 minute speedup which can't be used for troop training.