We considered the Churchill Crown but the issue is that there were or was a coin without the Sovereign's head.
Spinks have narrowed the field today for us by saying it was almost certainly a 'Commonwealth' coin, not a modern commonwealth e.g. Oz, but a Cromwellian period coin which numismatically is known as the commonwealth coin period.
So it is likely that the cc is commonwealth coin - but as for the W?