The blade to me looks like it has not done much more than 300 hours by the look of those caps. As for the stainless screws, that would only take one apprentice one balance with an old screwdriver tip to do that. The pilot obviously doesn't mind the dust but older blades not only wear the leading edge of that cap down, they erode a lot more paint further in from the tip. A good mustering pilot will have blades that look like that after a 1000 hours, one who is not so concerned or aware of what you see in the picture (just the erosion I mean) will do that quite easily in 300.