Those are indeed Paul Rebuffat's superb Spitfires. What a shame his site has gone, he made the best FS Spitfires EVER.
That P-40 I'm sure is on of Krzysztof Malinowski's.
Paul's Spits are posted at Sim-Outhouse. The file descriptions don't say which are Gmax or his earlier FSDS1 models. I checked out the Mk IXc in FS2004. As I suspected it's fine. All I did was to realias Sound.cfg. You could easily download Mike Hambly's Merlin sounds for it. The DVC gauges work perfectly & are also clickable. This makes me wonder if whoever uploaded them for FS2004 did so with his permission.


PS. I'm sure you're correct about the P-40.