Chuck and Dave were great to deal with
as suggested above give them a call as they will more than likely fix you up, great guys to deal with.
I have a C&C solo w/backrest, awesome seat just give it a couple of thousand miles to break in.
I think the Ultimate sits higher compared to the c&c & being 5'-6" that's an issue.
My wife is 5'-5", I had to lower the back of her bike & switch bars as she NEEDED a Mustang w/backrest