RAF Flying fortress

[Blackdog_kt]

This is an early model, distinguished from the different rudder shape mainly. The kind of tail we are familiar with (wide rudder with the fin extending over the top of the fuselage) was first introduced in the B-17E.

So this would make the one in your screenshot a B/C/D model. I don't remember if Boeing skipped a designation, or even exactly which type RAF had, but it definitely is an example prior to the E series.

These types were also lighter on the defensive armament, to answer your original question.

As for other information, i think that apart from using them in a few testing raids the Bomber Command was not satisfied even though the crews found them easy to operate. I think they passed them on to the Coastal Command and had them hunting for U-boats, just like the B-24s (again, initially these were mostly the early B-24D models without the powered nose turrets).