That's still WIP Doshii. The current idea is that they ran across some fragmented historical records, and based their current culture off of that. They're like parrots, mimicking us and hoping they're striking the right chords for whatever they're trying to do. One of the things I want most is to have them to boast of civilization, refinement, empire and history - how they know us better than we know ourselves - but in actuality, only have scraps. Bits and pieces. However, because they only have bits and pieces, the Ottyo had to fill in a lot of gaps themselves, so what they are culturally is not completely genuine.
That aside, the one thing I know for certain that I want with this faction, is to have them be British, or be based off of the British. Again, since that portion is WIP, the how and why are all still on the table.
As for why I'm doing the guns and whatnot first, it's to make sure GMs and PCs have a good set of stuff to interact with in RP. Since most of it early on will likely be primarily combat, the culture and all the rest can be pushed back. If I had to guess, most plots would do just that and start with some sort of armed conflict - big or small - and then try to unravel the mystery from there on, as the Ottyo are hostile.