In 1942, Rolls-Royce converted four Mustang Is into Merlin testbeds. I have seen drawings and photographs of these aircraft, but I still have some questions.
First, does anyone know if these were known as the Mustang X as in "experimental" or as Mustang "ten" as in the Roman numeral?
Second, what was the purpose of the enlarged nose intake? Did it house a supplemental radiator or an enlarged oil cooler or ducts for the Merlin's supercharger or a combination of these?
Third, the propeller and spinner appear different from those used on production Merlin Mustangs. To me, they look a lot like the units used on the Spitfire VIII or IX.
I'd appreciate any information anyone might have on these points.