Update:
Had to take a break from working on the Super Twin last week, reason being.....my 48 Watt Temperature-controlled Soldering Station simply wasn't "cutting the mustard" when it came to de-soldering the old mains earth wire from the chassis, realized that I needed a soldering iron with more grunt in it, so today, I went to my local Bunnings shop and bought a new 50/100 watt soldering iron, which proved quite up to the job, moral of the story.....if you're planning on doing servicing work on guitar amps, you need more than one soldering iron, a medium wattage one and a higher wattage one to de-solder those big solder blobs on the chassis, some amp manufacturers use the amp chassis as part of the grounding system, and the chassis can act as a huge heatsink, soaking up all the heat you pour into the solder joint, hence the need for a soldering iron with lots of grunt.
Of course, in hindsight I should have known that......
Stay tuned for more updates.