During the war they built Pratt and Whitney engines for Corsairs and Hellcats, and Hamilton Standard propellers, which I presume would have been fitted to a variety of types. One type they mentioned in adverts was the Corsair prop. They also built 219 Sikorsky helicopters. Be interested in the source of your info, as far as I am aware there was no Merlin XXV. Mark numbers up to XX used Roman numerals, and above XX Arabic numerals were used. Presuming a mark 25 is being referred to, they were used in the Mosquito VI and XIX and the de Havilland Hydromatic prop was a license built Hamilton Standard. Might assume Nash manufactured Hamilton Standard bits were interchangable with de Havilland manufactured license built Hamilton Standard bits.