MMO has to be in one server? Okay, well even if it can't become an MMO, putting out some banners would help advertise the game. So maybe instead of trying to make it an MMO, try to make it a known game? More active? Get the name out there?
EDIT: Saw your post chewbacca, and i would say to use new models, not the old ones. The new ones are more appealing.