I love the suit. Awesome.
Here's the sickle trainer I'm planning on using. I wound my Seymour grass hook in about 8 layers of electrical tape (to fill in the serrates and keep them from pressing through), then slit a piece of garden hose to put around the end and taped that, then a tip piece, then one or two more tape layers just for good measure. It may be overkill, but I didn't have a grinder, and I don't think it's possible to have too much between me and sharpened metal.
Anyway, I'm fairly happy with the results. Less ugly than I had anticipated, and it should be plenty workable for working through the plates.
Brian--I think we should both have one of these and one clean sickle for test cutting. That's a lot easier than jigsawing wood, plus the weight, balance, and handle will all be right.
You can also see the forward-sweep from this photo--is that the profile yours has? It seems a little further forward than I expected, though I don't think it really matters for historical technique. After all, it's not like sickle were standardized back in the day or anything.