Just to continue the 4-engined heavy bomber theme: I wish I could find a B-29 cutaway as good as that B-17G. I have some good cutaways of sections of the B-29 fuselage, but not the entire airplane. The best I could do is this somewhat simple Douglas Rolfe cutaway of the Boeing B-50D Superfortress
from the 1952/53 issue of Air Progress - History of Aviation
The B-50 was the last in the line of Boeing 4-engined heavy bombers that began with the XB-15, which is also illustrated in the cutaway. The "D" version pioneered the use of underwing fuel tanks, whch carried forward to the B-47 and B-52. Rolfe's annotations of the cutaway include some interesting items. Vertical and oblique cameras are shown located in the aft fuselage. This, together with the note about the range-extending bomb bay fuel tanks, makes me wonder if he picked up some information about the RB-50 version. These were used for shallow-penetration overflights of Soviet Siberian territory 60 years ago, and, of course, were very secret at that time.
I had a neighbor who served as a gunner on the strategic bomber version of the B-50. He told me that if it ever came of war, their crews knew that they were, in all probability, going on one-way missions into the Soviet Union. He must have looked back on his service with a bit of nostagia, as he purchased one of those sighting blisters, as surplus, and intalled it in a wall of his garden shed.