Hi Nosbig
Bad Dog!
It looks like you're in the UK? You should contact the Tamiya importer:
Give The Hobby Company a ring on 01908 605686 during office hours and they may be able to help you, just ask about spare parts for Tamiya kits. The MP4/6 has been re-released recently so they should.
Here's their website:
http://www.hobbyco.net/scripts/cgiip...s/ecommlogin.p
Good luck!