The Mercator was conceived as a replacement for the PB4Y Privateer long-range patrol bomber in the later stages of WW2. To achieve both range and attack speed one of the more appealing features of the Mercator was its powerplant configuration: two massive PW Wasp Majors sharing nacelles with a pair of Allison J33 jet engines.
A truly imposing beast, maybe too imposing, the US. Navy preferred instead a “less” complicated design, the Neptune. Curiously around twenty were produced anyway and they even saw service with the US. Navy, some of them in sneaky electronic operations.
Truly magnificent in size and superbly dressed in its overall Glossy Sea Blue livery.