Always figured it was the Dulfim. But it has me wondering, where was it until now? Docked with Island 1 the whole time? Who's on it? The original galaxy crew? Noone, and it's running on auto? Why didn't anyone notice it leaving then, they sure noticed the quarter quick enough. Doubt Leon would be so careless just to ignore it. As for it being Grace's base of operations, it seems likely. And you're not alone in forgetting it... but that's to be expected since we haven't really seen it in like what 16 episodes