I recently picked up some old blades off e-bay to try doing some restoration work on. There all pretty tarnished so sanding looks like it'll need to be done on most of the blades to bring them back but I've got an old Wade & Butcher Bow and Wostenholm Pipe that I don't want to sand because of the etching on the blades. Any suggestions for cleaning with out damaging the etch? I've got both Lynn's and Bill Ellis's disc's but there's not really any info on this issue.