So here I sit, sipping yet another glass of Spiced Pumpkin wine, with the answer to my question. The answer seems to be what it always is in these situations: if they don't make one commercially, and there isn't a common homebrew design, you likely don't need one.
I started this spring with the field as you last saw it in 2012. I pulled the few remaining stumps once the ground had thawed. I then ran over it a couple of times with the spring harrows. That pulled most of the shallow roots. I picked them up by dragging a set of diamond harrows. That also leveled the land somewhat.
I then went back over it with the spring harrows, a little deeper this time. More roots and rocks, but easy enough to pick up by hand. I then let it sit for a day or so while I spread some manure on it.
Then it was time for the 8" single bottom plow. That left large clumps and dug up more roots and rocks, so after picking those up, I ran the spring cultivator over it yet again. I finished it off with the rototiller. Looks okay, considering it was a forest in the fall.
Ms. Allis performed remarkably well through out the ordeal. The repairs done over the winter made a big difference both in performance & enjoyability. However, as always, with seat time comes shop time. The battery wasn't charging so I had to fix the regulator last night. The fuel gauge cap is to short for this style tank, so I'll need to find a longer one. The power lift group and bevel gearbox will need new oil seals, but they can wait for next winter.