Wow, there are SO many ways to merchandise a top round!  I must admit I'm totally  unfamiliar with some of these names such as for a, b, and c but I guess that's due to my age.  We just called b and c the loose side.  We called (a) either the lifter because you seamed and lifted it off, or it was called the deckle. We always cut off the loose side and used it for round cubes, ground round, or cubed steak. Then we sliced the solid side down with the first cut or two thick for a London Broil, then several top round steaks with the deckle left on for the round steaks, and the back piece for a top round roast.  Of course when London Broils were on sale for $1.49 lb we had to seam out the vast majority and cut them down for London Broils. All trimmed of course as we had a 1/8" fat spec on all cuts.  Or we seamed off  the deckle (a) and sliced it down for brasciole, or cut the solid side in two and sliced them down for minute steak or stir-fry. .  I had multiple cutting test templates in SuperCalc (predecessor of VisiCalc and MS Excel for the youngsters) so I could plug in this weeks prices and determine which cutting methods to push based on this week's prices.