I'd use the exact same head as the Shire to differentiate between that and the Bretonian battleship (not sure what it's called). I'd also make sure there was a pair of large 'arms' to grip the large asteroids. Mining isn't done by shooting little rocks, it's done by grabbing ore laden asteroids and mining them out, before moving onto another one. Shooting little rocks is just a game mechanic I think.
Maybe switch the engines to the rear as well, again like the Shire (I was watching one while I was Camara trading today, so it's drawing ideas for me). That would, again, differentiate it from the battleship. The underside needs a little more detail too. At the moment it's just flat, which is a little boring to the eye.