Baldwins bought the Deane collection in the 1940's or early 50's from my memory of their catalogue descriptions, so chances are that Peck would have seen this coin. I don't know if the earlier Deane ticket called it a proof, but it would certainly have been brought to Peck's attention if it was thought a proof at the time. It was an obvious currency strike to me - of course there are sometimes grey areas as to whether or not a coin is a proof, but this one was clear enough even at a glance. Look at the scaling above the breast for instance on the blown up LC photo. I think it fetched about £600 at the Bladwins sale.