Make that the left hand burner needs attention. It was the right hand side that I fired up a couple of days ago.
Seems that this stove has been involved in an impact. Both burners seem a little distorted (leaning) towards the front of the stove.
When I was testing the L/H side there was a mysterious fuel leak, I thought the control knob wasn't shutting the fuel off fully, but this wasn't so. And a couple of spirit cups full of kerosene later I discovered that the fuel leak was coming from the top of the burner. There was so much baked-on grime it has taken 2 days of soaking in the household acids and scrubbing to reveal that a tube joint was cracked. I silver soldered it up, and then found that it's opposite number had a small leak too so I have just silver soldered that too. It's sitting in the pickle bath as I type this. It's amazing how pitted the burner assembly is and how much rock-hard grime there was on it, I wonder if it had be run with the two leaks.
Still looking forward to making the spirit channels.