Electrolux caravan Fridge?

Just taken possession of a 1992 camper van
It has an electrolux fridge - no model evident, but looking at the starting knob and black push button at the bottom left and opening the "spy" hole I think it is campergas only.
The Knob is marked one side with numbers 1,2, and 3 and it turns to those numbers when pushed in.
The other side of the knob has a lightning mark on top and a gas flame mark below it.
So I am assuming it is a "Gas Only" fridge
I have pressed the black button repeatedly - no flame
I have pushed the knob in and pressed the button -nothing
I have pushed the knob in,turned it to 1-3 and pressed the button - nothing
To be honest I can`t see spark - does this depend on some connection being made to a 12 volt battery.
Could I put a long lighted match in the spyhole? without risk of explosion to see if gas is getting through

I think my question is is there an instruction manual on line?
Anybody any bright ideas - an Australian website suggested taking it out and turning it upside down a few times - it didn`t exactly say kick it, but I think it meant that.
Help Please-Thanks in advance anyone
Roger