General Electric HM-171 #2 Chassis
The chassis before restoration. Notice the cable crossing the power transformer. That was added for the speaker. On the right side you can see a bracket that was added to hold the speaker.
The two added tubes
The added tone and volume controls
The added controls, plus a capacitor and terminal strip added for the tone circuit
The components in the blue area were added for the audio output
The underside of the chassis after it has been returned to the original design
The chassis after cleaning, ready for restoration