65 Dometic not cooling enough

[Marabel65]

I have a 1965 AS Caravel 17' with the original Dometic M28a LP refrigerator. It had been working fine since her restoration was completed in 2010. I'm a snowbird and flock to the Gulf coast of FL. Near the end of my 3 month stay the frig wasn't cooling below 45 degrees and it wasn't terribly hot outside. I have been trouble shooting since I have been back in PA. I removed the unit from the camper and cleaned the valves and orifices. I fired it up and it cooled down to 32 in the frig and 0 in the freezer! It maintained for a few days then I installed it back into the camper. Now it will not cool below 45 again. The chimney is clear. The flame looks and sounds great. The baffle is what is baffling me. It says in the Dometic manual to set the baffle at 3 inches. 3 inches from what? I'm pretty sure this setting will affect the evacuation of the warm air created by the operation of the system. Any help would be appreciated since I will be heading south again soon.