They don't look like Termignoni to me as the outlets are different to all the termis I've seen. Do Termi even make 2-piece cans?
If they were from a Ducati Performance catalogue then they are probably GioCaMoto as they used to make some of the Ducati Performance parts.
I have a PDF file of an old Ducati Performance catalogue on my computer, showing these and Arrow exhausts and they look like they could be the DP parts. I can email you the catalogue if you PM me with an email address.
BTW, the marking 'SX' is an abbreviation of Sinistra (left) and 'DX' an abbreviation of Destra (right).