Here's another one that I wrote for a different thread. Note that there were several plans for a Shackleton replacement. This is whey there are 50 Atlantics/Orions, OR.357 and refurbished Shackletons.
The AW/HS681 is what really makes me shake my head in that list; developing a brand-new, ultra-fancy, expensive transport plane that does exactly what the Hercules and Transall does with a shorter take-off run.