I have a Cross Metropolis on the way to me, and the nib does not quite match what I'm seeing in my research. It has the skyline engraving but also appears to be hallmarked 14k or 18k gold? The other Metropolis nibs I've seen are all gold plated steel with no hallmark.
It is the gold plated and black model. The pen is boxed and has the original barcode label on it, but none of the numbers make much sense to me.
Any ideas? Possibly an up-market model? I can take some pictures tonight if anyone is interested.