I think what Absinth is trying to say is that part catalogues do come up for sale around the place. If you're really keen then try and buy one (although they can be expensive).

Some people who invest money on these items generally don't share what's in the catalogues and the data they gather from them, because they have invested lots of money and time in them and they are reluctant to allow the general public get it for nothing.

Personally this is not my view, I think knowledge should be shared and referenced among a greater audience for the benefit of maintaining the history and knowledge - who is to say the one who holds 'the book' should be the fountain of all knowledge? This is exactly how cults start.

Some years ago I was part of an online group of hobbyists that built flight sim cockpits. I mean the real 1:1 deal with real military spec parts and all the bells and whistles - I actually owned a Martin Baker mkII ejection seat and canopy from an F-16. I have sitting on my bookshelf a couple operation manuals for the F-16, F-15C and F-18A/B. They provide everything you need to know about flying the aircraft, servicing and even some tactical data. I paid a bit of money for them, but we were happy to share the knowledge, because we knew that in doing so many more people got enjoyment out of their hobby and the interest grew because of it.

Ultimately it is the person who owns a book, car, part or whatever it is their choice what they want to do with it - whether to share it, withhold it or burn it.