First, I would have stayed level for a bit so I could get a good estimate of his E-state.
If he had more E than me, I would have started a gentle flat turn and gradually tightened it as he got closer, eventually pulling up and rolling in the opposite direction so I would be behind him after he overshot. If after that he tried to turn with me, I'd follow him. If he pulled up to reposition for another attack, I'd push my nose low to pick up some speed and extend, and get him to burn more E for his next pass.
If I had more E I probably would have started a slow spiralling climb to the right, dropping all flaps just as I was about to stall to get my nose 90 degrees up. From there the 38 flips over and the nose drops straight down so he'd hopefully be stalling 400-600 in front of you.