The secret of goooood dutch-over cooking it getting a meal done on time 's l o w e l y' !
Most heating fires are to hot.
If you can scrape a few ashes to a cooler corner of the boiler it should work, but why not dig and brick-line a place for it, if you the room?
Getting at the d-oven would be a concern, I like the idea and hoping for pictures!
Here is one that works very well in a hunting camp.....
Spray the inside of the oven, even a real seasond oven will stick this trick.
Dump in a couple cans of pie-filling, don't matter what, you can even mix them if you want, peach and apple just for a say.
Over the top dump in some Bisquick batter, cake batter, what ever suits your fancy. (tried it with pancake batter, not as good, but we eat it, Bisquick is best for me)
Slooooow cook this one, with just as much or more even heat from the top as your getting from bottom. When the upper layer of crust is a good brown, trust the bottom is also done.
Scoop out to serve, dump some of the slightly carmiled pie-filling over the baked batter, with a scoop of ice-cream on top and you can get parlor tricks out of folks in a hunt camp, my guess is it would work at home!