I think you have a great idea and a great image here. I am surprised it didn't score better in the challenge. Perhaps because it was US currency and this is sucha diverse international audience that may not know about the old wheat pennies.
Still a great shot and one to be proud of despite the score in the lower 5.
This is clear and fairly well focused (not quite parallel), but for some reason just doesn't "feel" Black & White. Mind tricks perhaps - used to seeing a penny in copper tones maybe so I see this as sepia. Nice macro nonetheless. Good luck in the challenge.