Link is to the real thing, but there are copies kicking about. There is a guy on eBay appbiz? Something like that who makes a copy (strap and hole to my mind is not right)
Plus Mike was doing door panel GB. There was talk of a GT panel option but I don't think it came together
One of the tricky bits to replicate is the metal rectangle trim that goes through the panel. That (and the incorrect strap) if I recall is what is missing from appbiz
I managed to find a pair of trims in Germany, if you wanted to copy them I'd be happy to dig out from the stash, photo and measure for you
http://www.pbase.com/9146gt/gt_door_panels