Welcome to Librarium Online!
My Current Armies
Dwarfs 7000pts, HE 3500pts, VC 2500pts, Menoth 2500pts
See them at Stumpy Heaven
Looks pretty good but I have two suggestions
Remove the mold lines from the cannon (they really stick out) or if its just the pieces not fitting together well fill it in with GS.
You may also want to reposition the dwarf with the ramrod/swab so it looks like he isn't just cleaning one of the axles.