Alex, I have added you to the team as a provisional 3D artist, you should now be able to view the thread that Post Captain referenced above. Let me know if that is not the case.
As for rewards, I have been volunteering here for well over a decade mate, and I can't even begin to describe just how rewarding that has been to me personally. I have learned more here about many different subjects over that time that I could ever possibly quantify. Gaming, game design, computer hardware and software, modding, modelling, programming, history, psychology... not to mention the great people and friends I have met along the way, the list is almost endless too! Anyway, you get the idea.
Unfortunately we can not offer monetary compensation, but this project is the first of it's kind, and getting your name attached to it may be much more rewarding in other ways later on down the line. Once we get to a point in development when we really have something to show off, there will be a big media push to make sure people notice us! We would certainly be glad to have you join us!