Good catch on the Guignardia, Melissa. Lesions running parallel to the direction of the veins is a clue as is the ruff feel when you run your finger over it. Funny, today at our orchid club meeting I spotted some on a Vanda that someone had brought in to show. When I discreetly told the alpha male, it was segregated and hauled away. It is evidently a serious problem on Vandas here. It sounds like you are on top of it so I'll just wish you lots of luck.
Jim