Argh. I'm getting nowhere fast. I was hoping to decode the IFF using Thomas' IFF tools, but it just doesn't work. There's a range check error, and it crashes. I also tried decoding them in WCPPas. That works slightly better, in that it doesn't crash, but extraction of the images still seems pretty much impossible.
However, looking at the Armada cockpit files, I notice that the hands are not included in individual ship cockpits. Therefore, it's quite likely that the WC3 hands are also not included in the ship cockpit files. It may well be that this hand file will be easier to use, because it will probably be a pure graphics file - which the cockpit file is not. The cockpit file includes various other stuff, and that's probably why we've got all this trouble. Needless to say, if the hand could be extracted, then you'd only need one screenshot per ship to get the other parts of the cockpits.