I agree w/ John. Lowered price and I bet there were some lookers who didn't like what they saw on that floor & tunnel. I'm guessing maybe the left side was parked towards the ocean and exposure to wet salty air, the other side tucked into a building w/ overhang, more protected but who knows. Check the front wheel rusted left side but not the right.
Still 1600 for a 2900 mile P200 motor, fork, headset, clean cowls & mudguard(w/ reflectors), decent seat, BBQ rack w/ desirable back rest and even a lovely tractor tail light. Add all that up and tell me what you come up with.