I have a Husqvarna 345FR. The saw blade that came with the unit was the Scarlet. After a few sharpenings the blade is done. I purchased some Maxi blades and they certainly cut better. It was recommended that a round file be used to sharpen. After a few sharpenings they are toast as well. The pic shows the two cutters. One on the left has lost the top point. The one on the right shows the business end starting to trail the gullet. Can I dress these blades up with a flat file? Should I be using a flat file instead of round? I am cutting small trees at ground level and I don't mind hitting it with a file if it runs in the dirt or a rock.