That was a sort of "sneaky catalog". It is titled a manual, and does contain some shooting tips, but has photos of many of Colt's guns as well. It was printed in the 1950's and probably distributed through Colt dealers and by mail. I have bought a couple of them that were in manila envelopes with the Colt factory return address. Some are found in gun boxes and may (or may not) have been put there when they were packed at the factory. I doubt anyone knows for sure by now.