By the time the second world war started the Consoladated PBY was already obsolete. The Navy had already ordered its replacement the Martin PBM which was better in every mesurable way - speed, payload, range, etc. But the venerable PBY was ready, it was in production, and it worked. Over four thousand were produced, vs about 1200 PBMs.
This book gives the history of the design of the PBY, and talks of its use, concentrating on the units that worked in the Atlantic where it did all of the tasks that you expect of a patrol bomber, escourting convoys, light cargo movement including people such as Eisenhower and his staff from England to Gibralter where he commanded the early stages of Torch, the invasion of North Africa.
It was also a PBY, a Catalina of the RAF that first spotted the Bismark (not to say the pacific fleet at Midway, but that was in the Pacific war).
The PBY was probably not the prettiest airplane with it's angular features and it's wing having to have support struts. But it had a workman's appearance when compared with the PBM, king of like the B-17 when compared to the B-24.
This book is well written, profusely illustrated and exhaustively researched.