Elmshoot, you're going to kick yourself when the answer is revealed, based on your sig!
New clue:
1. 150 were ordered but the orders were cancelled after only a few were built. 2 were prototypes and the remainder were production aircraft.
2. It was originally intended to be an evolutionary update to an iconic aircraft, but as time went on the number of changes became so substantial the designers decided to change the name. Strangely though, the "mark" number was carried over from the previous aircraft even though the name was changed.
3. One of the changes made to the aircraft from the original design was intended to give it the fastest roll rate of any existing aircraft of its type.
4. One of the major changes made to the aircraft from the original design was in an iconic feature of the original that was so successful that the operators really came to desire it in all new designs during the course of the war, and looked sceptically at new designs that did not have this feature.
Last edited by JohnnyS; 08-15-2018 at 07:50 AM.
Reason: :)