Well, I don't have any experience with your particular fridge, but it should work like other RV models.
The electrical system causes a little heating element to heat up. You should be able to follow the wires in the back of your fridge to see where the heating element is. Turn it on in electrical mode, and wait for an hour or so. Check the area where the heating element is installed and see if it is getting hot. If it is, then your electric heater is doing its job. If it is not getting hot, then your heating element is probably shot. These are replaceable for around $50 or so. If it is getting hot, then make sure the fridge is level, and let it go for a good 12 hours or so. Put a thermometer inside so that you can really see if it is getting colder. IF it isn't getting cold, then you may have a leaking coil--see below.
Now to troubleshoot the gas system. You say that you have the pilot light lit, but you are trying to ignite some gas using the little flint striker, right? Well, my guess is that the flint striker is there to get the pilot light lit. Once the pilot light is lit, the thermostat in the fridge ought to be opening up the valve to make the fire that heats the system up. If this isn't happening, then either your thermostat is not doing its job, or perhaps there is some safety feature keeping it from happening. You might be able to "jump" the thermostat to get the gas to flow to the burner--this would at least allow you to test the fridge's ability to get cold.
The safety feature I am thinking of may be a pressure switch that only allows the system to fire up only if there is the right pressure of ammonia gas in the system. If your gas has all leaked out, then neither your electrical nor gas mechanisms are going to do anything. You may need a new coil. You ought to be able, again by following the wires in the back of the unit, to determine if such a pressure switch is present.