as depicted (inaccuratly, i'm sure) in the movie 633 Squadron, the mossies that carried the cookie did not carry a bombadier, but did their drops fighter/bomber style...according several detailed mossie web sites (esp.
http://www.home.gil.com.au/~bfillery/mossie.htm <--- best mossie site i've seen
&
http://mossie.org )
the Mk.VI did not carry the cookie - mks. IV, IX, XVI & 35 did
other interesting heavy weapons carried by mossies:
57mm cannon (Mk. XVIII)
1050 lbs "uncle tom" rocket
94mm cannon (not in combat)
18" tordonut
never heard of mossies w/ gun other than foward facing, but apparently there were some w/ a variety of defensive guns:
4 gun dorsal turret at rear of cockpit
2 x 0.303" remote rearward machine guns in the nacelles
1 x 0.303" remote rearward machine gun in the tail
Mks. IX XVI 34 & 35 had ~40% extended range with 200 gallon drop tanks