I thought the community might have split in two parts. One who thinks that the last plane is too easy (and nobody of this group wants to get blamed for taking the cherry from the cake), and one who needs more hints.
The basic type was built more than 100 times. However, if you google for pictures with the type's name most of these show this very specific variant. It became famous with an extraordinary flight and it differs from its sisters by the engine and, most prominently, the coolers. This is why I thought it would be better to ask for this special variant.