It's unobtainium, that's what.
My friend Pablo McCain is Dale's welder (and they are both married to a pair of sisters).
They used my bike to see it they could put together an exhaust system based on the old Hindle 4 into 1, but the price point was more than most miniceptor owners wanted to spend, so I have the only one.
You can probably get the slip-on, but would have to make the header and mid section.
Sounds like a small Ducati Desmocedici.