A classic Optimus 8R Hunter petrol camping stove.
It had become rather rusty and dirty having been stored in a damp garage since the last time I went camping, mumble years ago. A good clean, polish, and a respray later:
Incidentally the paint colour is called Royal Blue, but it's a fair bit lighter than the Royale Blue I painted Fenchurch in.
My dad bought the stove new when he first started climbing about 40 years ago, and he lugged it up and down mountains all over Britain and mainland Europe. Optimus is a Swedish company that started making camping stoves in 1899 and still makes them today; in fact they only discontinued this model a couple of years ago.
The main disadvantage a petrol stove has compared to a bottled gas stove is that it takes a few minutes to start it up because you have to get the vaporiser hot enough to boil the liquid fuel. You can pour meths or squirt a special "petroleum paste" into the trough under the burner, or do as I do and warm the tank with your hand with the valve open until petrol dribbles out of the jet and drips down into the trough. When you've got enough fuel in it, close the valve, light it with a match, a quick "woomph" of flame singes the fine hair off the backs of your fingers, then you wait about a minute for the burner to warm up...
Just before the preheater runs out of fuel, open the valve and it should fire up with a roaring blue flame. The flame is a bit weak at first, but give it a couple more minutes to get up to full running temperature, and it's at least as powerful as a gas stove of equivalent size and weight, if not more so. It certainly puts out quite a bit more heat than our cheap Calor Gas stove.
The brass burner glows red hot in operation. It took 7 minutes from cold to boil 0.5 litres of water (more than enough for a mug of tea) in an open pan. I reckon an additional 0.5 litres would probably take less than 5 minutes.