disclaimer: I hardly know anything about the Deltas, other than the common wisdom that they were sort of like the Kardashians... famous for being famous (or infamous). Beautiful, but heavy and not good performers.
Since I already had a browser tab open to Velobase, I took a look at what it has. It does show the C-Record Delta looking like what you show... the parallelogram in the brake has 4 points where the linkages join.
When I look at the page for the Croce d'Aune version of the Deltas, the lower point where the linkages join is actually 2 points. Maybe this is what the "five pivot" reference means?
VeloBase.com - Component: Campagnolo Delta, Croce d' Aune
(hopefully the link works)
Steve in Peoria
(no Deltas for me, but I do have a pair of Campy monoplaner brakes, just cause they looked cool.. yeah, I'm shallow)