@brainiac
Technically, that looks great already
Also, try to leave the longer leg as long as possible, before winding the extension around, as you've to wind the longer leg once around the resistor core, before bending it down finally. Tom just bent it straight down, for his old PD log. Winding it around the core once, helps centering the resistor within the heater cover and also creates turbulences in the air flow, which gives you much better heat dustribution, bit more draw resistance and much better vapor production
Not sure about that solder again, though. Sorry
But not your fault. Description in the ebay link doesn't make sense! What you want is high temp solder with less tin (Sn) and more copper (Cu). Sn97Cu3 means 97% tin (Sn) and 3% copper (Cu).
Link above says, it's type C99, which usually means 99,3% tin and only 0,7% copper. That's the same mid range temp solder, you had before, just thicker wire. Description reads '
99C - 97% Sn (Tin)99.3% & Cu (Copper) 0.3%, which is nonsensical. Is it 97% tin or 99,3% tin? And copper content is only 0,3% here? However you add that up, never makes for a full 100%. So the seller probably got confused himsef about that, when he created the offer.
Here's the solder you need:
https://www.amazon.co.uk/Sn97Cu3-DIY-Tools/s?ie=UTF8&page=1&rh=n:79903031,k:Sn97Cu3
As for the DC jack... flattening the inside wall a bit with a file or 40/80 grit sandpaper is one optiin. Getting an M11 X 1,0 thread cutter bit and cutting threads into the wood itself is another
. Then you won't need the nut. Cutting threads across the grain is no problem.