The pic doesn't reveal so much, but looks like whoever did this was using an external power supply, and not the original internal one. I have a C/21 in "original" condition (purchased two years ago, used, from someone who took care of it, and it was perfect) and the only "mod" I made was to step up the output voltage from the internal power supply by a couple of volts, so now it runs about 40-50W output power and nothing else is harmed. The mod involves changing two resistors in the power supply. For its simplicity, it's a solid rig. I just used it to make several contacts on 20CW.