The only places magnetic wear particles might come from on a stovebolt engine would be the camshaft, lifters, distributor gear, etc, and maybe a little internal wear in the oil pump. Most other bearing surfaces have soft metal running against steel, such as rod and main bearings, timing gears and such, and even if those parts wear, a magnet would be of limited benefit. Cast iron pistons and cylinder walls are magnetic, but wouldn't the wear particles from them be trapped by a bypass oil filter?
Jerry
