The substance refered to as lamp oil is the fuel we use in greenhouse heaters,Tilley lamps etc,it is of minimal octane.
TVO should be around 50 octane and can be mixed from 28 second home heating oil a drop of petrol
and a sqirt of lubricating oil,sorry I cant tell you the exact quantities as I mix it so the exhaust fumes smell right.
It has been legal to use home mixed TVO fo a couple of years or so.