Ebony makes a great accent, but i think you'd need it in one more place (for a total of 3) for it to work correctly. I do like the idea of recreating your neck lams in the places you mentioned and for the cavity cover. The sapele involved in that will look fine if you use a grain orientation totally different from the body grain. That will look intentional as opposed to mismatched. You could even orient your lams offset by 30 degrees or (pick a number) in each of the three locations: TR cover, HS nameplate, and cavity cover, just make them all point the same way for continuity. In other words if your neck lams run at 12:00 and 6:00 o'clock, the other 3 locations could run at 1:00 and 7:00 o'cklock. Just one option.
SR