To the best of my knowledge the EA50 and EA50T had two 6AQ5's not 6BQ5s.
Also they only had a volume comtrol, no tone stack.
http://www.schematicheaven.com/gibso...maker-trem.pdf
Yours may be a later version, but I can't find a schematic that shows the tone controls or the 6BQ5s.
Winnie