If I were sorting slags or striped transparents/opaques (or any similar type of marbles that could be by 2-3 (or more) different makers, I would be doing the one-seam, two-seam idea of yours. As Steph mentioned, others are usually sorted out by company and style - Pelts, Akro corks and other obvious styles. Patches, to me, is a whole other ballgame in ID'ing. I've given up on those but, after studying the various tips, etc. on the marble boards, you should be able to sort those by specific patterns.