Take a look on ebay.co.uk for a shield. It's unlicenced, and I'm pretty sure the "engraving" is just paint, but it may be what your looking for?
I just want to say that I think, when the visor is down, Pete's helmet is absolutly STUNNING! I really love it, it's got beautiful lines, elegant, but still looks mean at the same time. I'd love to have one of those!
EDIT: I found the same shield from the makers own website