Well, I did it. Made duck soup. And it turned out to be surprisingly good. Even BW liked it, as did my pup. I made one major error, 'tho. (I'll explain that later)
To begin with, I took a wing and a thigh from the "left over" carcass, and boiled them for about half an hour in 4 cups of water. Then I removed them, let them cool, and removed the meat from the bones, which I gave to my furry garbage disposal. Chopped the meat into bite sized pieces, and removed any skin. The remaining stock had a reassuring bloom of fat floating on it.
Meanwhile I sauteed roughly equal and generous (making enough for only two of us) amounts of thinly sliced carrot, celery, and diced onion until flecks of carmelization appeared.
Then added the mire ppoix and the meat to the stock, added a bit of salt and freshly cracked black pepper, a fresh bay leaf, sage leaf, and fresh thyme and oregano, and let it simmer for about an hour.
Having noticed the flavor enhancement of both spinach and sauvignon blanc to the roast duck, I tossed in a generaous handful of fresh chopped spinach, then messed up the whole thing by adding too much wine. Up to that point I'd been tasting it and found it quite good. The wine all but destroyed the duck flavor.
In hope of saving the soup, I poured it into a bowl and refrigerated it overnight. That helped. We had it for lunch a few minutes ago, along with italian bread and a glass of chianti. The more of it I ate, the better I lliked it. BW said she found it very good, and is actually anticipating my making another batch of it. (The rest of the duck carcass is frozen, so I'll do it again in a couple of weeks, being sure to leave out the wine!
All in all, duck soup was "duck soup" (easy) and flavorful and satisfying. Now I am truly baffled that there isn't a plethora of recipes for it. It's as easy as chicken soup, and has a nice flavor.