There a set on fleebay now but they are already at £100!!
http://cgi.ebay.co.uk/Ford-Sierra-RS...QQcmdZViewItem
AMI (Nick Phelps) Model makers manufacture the new ones but expect to pay around £60 on top of that. Mind you they are spot on - only the alloy backing is missing which you don't ever see. Does make them tricky to fit but with care it can be done very well.
One of mine rather famously came off at Silverstone and he replaced it free of charge as that set had bad glue. New ones are on solid
enquiries@ami-models.co.uk
01296 663277