The fenders look stock to me. They have just been painted and the front has had the U brackets removed and the holes filled. I also think it would cost you quite a bit to turn it back into a stock bike. You have the unicorn tree, gauges, and chain guard but you are missing the exhaust and you would need to get the fenders re-chromed, a new wiring harness probably and the turn signals/mounts, correct grab bar. It adds up fast. Nice bike though and a good price too. In this instance the fact that it is a K1 doesn't make it anymore valuable than a K2-K6 in my opinion because it is not stock.
Scott