LIL' late with this note, but part 3 is out since last weekend. The regulator works perfectly, the lil' green light so happily blinks at me when iron is at good temperature.
Basically I managed to did it. I turned 5$ Soldering iton and 10$ worth of parts into functional 100$ soldering station! Ironing tips don't go to waste prematirely, soldering jobs easier because of ability to set right temperature.
Thank for all'ya support!