Congrats on your success!
With SBS6 and IA7 at pretty close to far ends of the arc from each other, there's a chance that your setup is still just a wee bit off; there's interaction between dish elevation and motor elevation that will "flatten" or "sharpen" the shape of the arc depending on settings. For example, I had to raise my motor a degree or two and drop the dish an equal amount (or was it the other way around?) to get it to sweep the entire Clarke Belt just right.
ONN, to the best of my knowledge is 24/7, as is White Springs. I'm confident that you'll get those locked in in no time!
Bob