The fridge in my 75 does have access from the rear, but it is not required to operate the unit. Inside the refrigerator near the floor is a series of knobs to control the unit. There is a gas / electric knob that should be in the gas position. To start the unit there is one knob that you pull and hold out, it is located to wards the left side. Next to that there is a button you push in that causes a spark. There is also a sight glass at that end that will show you when you have a flame. Do not release the knob you are holding out until the flame has been on for 20 seconds or so.
That is pretty much it. I always turn the stove on first to get as much air out of the lines as I can before I start the fridge. Also, too much light in the trailer will make it hard to see the flame in the sight glass.
WBCCI President 2016-2017