so, been getting a fanmade codex together for my Chapter's codex - Codex: Iron Dragons - and it is planned to have numerous things in it that normal GW-published codexes won't, such as actual Mechanicus units, Mechanicus wargear and items, and some fluff that will actually last you to read ;)
so, basically it boils down to this; I could use some help in the playtesting area, to make sure that the rules are balanced, no units are overpowered, and generally see how people think of what's presented in the codex, thus far
so, if you would like a copy of said codex, then please, by all means, send me a note, and I'll send you a reply with a link