Sorry, I don't have what you're looking for, and it's going to be hard to find. I've owned Lo-boys for years, and I've yet to even see a 222 sickle mower for a lo-boy. I think I've only ever seen one on e-bay. You might be best off to take some photos and post them here so that folks can see what you've got and what you're up against. Several of the guys here are machinists, and several are excellent fabricators, so there's a good chance that someone can help you out, but we've got to see what you have.
1951 Farmall Cub, Cub Cadets 102, 104, 1811, 1864, Simplicity Legacy XL 4x4 Diesel with FEL, 60" mower, 50" Tiller