Well I have slowly started adding age washed to the junk, though its kind of hard to see in this pic;

Thank you everyone for the advice concerning the big gun.
While the junk's washes dried, I started adding stuff to the gun;


I'll be adding a nice big heavy metal washer to base it on so it will not topple over.
It will not be permanently attached to the junk, as the junk also has to do double do as an innocent junk upon occasion.
That way it can be used on other ships or maybe for harbor defenses to.
Thank you all for your kind words and C&C.