I would like to replace the Avon Roadriders that came on my 71 R60/5 to a more vintage looking tire. The look I am going for is that bulbous semi-knobby, what would have come on it originally. What can I get away with size wise with stock fenders and suspension, and what options are out there? The Avons just do not look like they belong on that bike at all, to me. I would much rather prefer some Heidenau K somethingorotherz, or the like. My bike is not the purdiest in the world and I do not carve corners scraping knees like on my K-bike so I am basically looking for that old original balloon look. Thanks for any advice.