To Ian Smale, and others: The last time I bought a set of air filters for a 58 300 from Atlas Motor Parts, I was told, with kind of a smile, that they were actually readily available as a part for airplanes. I don't know any of the specifics, and I didn't look into it as I no longer have a need for any. But if I did, I would check it out. When you try to buy them as a part for 300s, they can be pretty expensive. Larry carrel [Non-text portions of this message have been removed]