I've seen it yesterday on Dallacolombina catalogue. I understand it's the same gun with a different band set (single 17,5mm stinger). I think this choice is to match the requirements of the european market, where it's quite uncommon to use a double band set (except on longer guns like a 110+). Many people here in Europe have indeed bought the double band Gabbiano but ended up to use it with a single band, that is better for our bream/bass/mullet/rock fish hunt. And a single 17,5 has obviously more power than a single 16.
Me I rest my case: for shorter guns like the 80 you're looking for, all these discussions about extra power are pointless, IMHO. I use my Gabbiano 77 with 16mm single, my C4 100 with single 19mm and my Snake 120 with double 16mm. That's the way they work fine for me...