Wookies, though not appearing so, are VERY technologically adept. Hence why Chewbacca could repair the Falcon (Not an easy craft to keep space worthy!
) It has been mentioned in the Role playing Game and several books, that wookies have great technical skills, and of course great strength
. It also mentions that Wookies are found throughout the galaxy, implying that wookies have spaceflight capabilities. And in one book, our heroes travel to Kashyyyk (sp) (the wookie homeworld) were they do in fact live in trees, however they are at the same time very advanced cities in the trees. It is nothing like the ewok village in the trees!
But as Leon mentioned, NOWHERE does any reference material (canon or not) does it mention or describe or picture any wookie spacecraft specifically, Lcasarts took creative license so all those vehicles you see for the wookie civ are Brand spankin' new (again as Leon said above)
So relax and enjoy pullin' arms outta sockets, because Wookies are tech heads too!