Hi Billy
I am assuming the audio valve you are seeking is a PCL82, as that was the usual audio valve of the time, in which case you can get one on ebay if you are a bit quick....
http://cgi.ebay.co.uk/PCL82-VALVE_W0QQitemZ180131531001QQcmdZViewItem
or
http://tinyurl.com/2zotyw
Hope that helps.
Lee
Lee
June 2007