Williams did their own radiator Richard. AFAIK they still have their own. I had a good look during an open day around 5 or 6 years ago. This was prior to Simon leaving Mulfab to start on his own as SiFAb. So, a choice of three suppliers Peter.
Graham (G4FUJ)
Sold L44FOR 4/4 Giallo Fly '11 MINI Countryman Cooper D All4 '90 LR 90 SW