This may help. Not an insert but a grille shellI
http://www.freewebs.com/rmrresin/nforderingcontact.htm
Although he is a bit behind at the moment. I am still waiting on stuff I oredered a while back.
I enquired and he said he was 6 to 8 weeks behind. His response to my enquiry was quick though.
Geoff aka whodaky