When I needed a replacement card in Venice, Italy the card was manufactured on a generic Amex blank at the Travel Service office while I waited, it did not include the artwork of the original card. This replacement card was temporary, valid only for a few months, and I soon received the official replacement.
I do not think there is a visual difference between USA and UK Platinum charge cards, unless the UK card has been recently updated to include a chip. I also do not believe that any American Express Platinum card is valid for admission to Virgin's clubhouse, unless you use it to purchase an Upper Class ticket
. This may be a Centurion benefit.