Here is a Lancaster B.II in Coastal Command maritime patrol guise.

From Weaponsnadwarfare.com (great site);

"Designed as a back up in case Merlin production was interrupted, the 300 Hercules-powered Lancaster Mk.IIs built were dropped by Bomber Command in the interests of commonality in autumn 1944. Because of their better performance at lower altitudes many of them found their way to Coastal Command, operating alongside Liberators in the long range anti-submarine role.

Bulged bomb bay doors and ventral turret were removed to reduce drag and nose-mounted Yagi aerials formed part of the ASV equipment. Front turrets were faired over and provision was made for 4 fixed 20mm cannon in the nose, although only 2 were often carried. Some aircraft had their upper turrets removed to save weight and increase range."

This particular example carries two 20mm cannon (these are armed with AG1) in the fared-over nose, aerials for the ASW systems are also visible on the lower nose section. The upper turret is reatined too.

The bomb bay is the standard version (not bulged) and is filled with some general purpose bombs and five torpedoes.

Other than the front turret being removed, all else is as per the Lanc B.I.

Good hunting!