For me, there are way too many frame tubes at the rear end that need to be covered or simplified. If I were going to hack the frame about, I think I'd want to go much further with the transformation. that frame is designed for two up with bags etc, so for a single seat, it could use a really light subframe.
wait a minute- did you say $2500 total including what you paid for bike? Nice score!
The old school Ducati logo really makes it too.