Another stove out for the first time in years. It took 12 minutes to boil two cup-fulls of water, meths fired and took a blow down the filler to get any priming meths flowing! It will need a fettle...
Yes, all unscrewed. On the blue/yellow Turm Sport the control knob is is screwed into the filler cap when stowed, when in use there is the vent, it's a neat device. There will be some sort of packing in the longitudinal tube, and there's loose rust in the tank which is probably adding to the problem