On the fridge, I as well will assume that the 39 degrees was Centigrade, but the fridge temp is Farenheit, yes?
Don't get discouraged, but I think that you're asking/ expecting a little too much from your refrigerator.
If the camper interior temperature was that hot (100+/- deg. F), there is no way that the kind of fridge we have in the coaches should be expected to maintain a cold temp. of 40 deg. F. It just won't happen. I drive a refrigerated truck here in the states, and even with a commercial refrig unit, the temps get nowhere near that (40) most of the time when it's that hot.
Most food will store for at least a day, if not two, at 50 degrees, as long as it is thoroughly cooked when it's time. No rare steaks, ya know?
The BEST way to be sure of your food is to freeze it at home, and defrost it in the fridge while waiting to cook it, and then finishing the thaw by running COLD water over it (or defrost in the microwave) before cooking time.
Another is to just purchase soon before your cooking time (but that's a hassle).
There are products out there that can replace your fridge vent cover up on the roof with a solar powered fan (supposedly draws or blows the hot air out of the coil area), or that can be placed into the fridge (battery powered) to blow the air around a bit more.
here's a couple good links:
I know that there's a chart showing the maximum hold times at varying temperatures somewhere, but I can't find it and need to go to bed. 75,ooo pounds of product delivered by hand truck so far this week (3 days), and 1000+ miles down... one day left before the weekend....
don't give up!