Hi! Sorry for the late reply! The models were compiled and ripped by Krishty. You may look for his website by typing in google "Krishty Ace Combat" and the first result, should be his website. There, you will find the Lean Viewer with all Ace Combat 3 vehicles/map models.
Have you considered releasing a texture pack? Beetle HW (PSX emulator) can swap out textures now, doesn't even have to be the same resolution. I wanted to make one for AC3 but it's a lot of work and time that I don't have at the moment.