Maracyn 2 is great, you don't have to use the marine one as the freshwater one is the med and marine version is the med plus vitamins. Petco sells tons of it so it's "probably" not expired. If the fish still has any sores, fin erosion, filmy stuff or other skin abnormality I would dose it because it will help prevent bacteria from infecting the spots where the trophonts were. A lot of times (according to a fisheries trained wholesaler friend) it's the secondary infections that kill the fish rather than the ich or brooklynella. He had me treat 3 anthias with brook with maracyn 2 and all 3 recovered. A vet I talked to day before yesterday says either maracyn 2 or oxytetracycline is a great help to fish with skin infections and not as dangerous as some of the other products.
Good luck, I have a soft spot for these guys too. Got a gorgeous powder brown about 6 months ago, it's doing fine. They are stunning fish.
Kate