I tried that (The F-1), and almost beat him. He managed to turn his plane around in half a second and shot me down. The F6F/A6M5, however, was easier. As long as your mobility is high, you have no issues with missiles, only AA guns. Either way, it's still very hard.
What I did, was the maneuver that all AS aircraft do. And that was flying back and forth across the mid-portion of the map. Everytime I would approach a Varcolac unit, I would try to fly with them for a bit, then I would carry on with my path. Also, perform lots of semi-loopty loops. If you fly right into the middle of it all, then head stright up, climb altitude until you hit about 17,000 ft, then drop back down and try to hit them with everything. Another thing to note when I had almost completed it: I had a minute left.