Never heard of it but a little digging showed that the set is a Hitachi AP22 chassis and the service manual can be downloaded from the following link but if doing this ensure all parts are downloaded before opening but also scan for viruses as you never know.
http://www.eserviceinfo.com/downloadsm/11334/Hitachi_46EX2B.html
This company appear to stock Hitachi spares by ordering with the Hitachi part number which may be obtainable using the service manual or contact them to see if they have it.
http://www.unionel.com/website/index.html
sparky
May 2006