I don't know if you live in the U.S., but if so, would you be interested in selling your bottle of Onyx? What size bottle is it? (tried private message, but I guess your inbox is full).
Sorry it's taken me so long to reply to your message - I usually don't log-in when I visit Basenotes, so the whole message thing escapes me.
Anyhoo, I am not sure about the provenance of the JH EDP that you describe. I (coincidentally) just got a new bottle of the EDP for Xmas, and I have literally just had a good squirt to see if I can detect the "metallic" note in mine that you all smelled in your bottle. I can't. All I can smell is the spices. I suggest you could have a spray at Sephora then go home and compare!