While the group and model are unknown, I do know that these were short lived. Campy introduced 8sp in 1990/'91 so you don't see many of these. The photo shows a 14-26.

update: this may actually date to approx 89.  None of the 1990 catalogs show an option for a 7sp cassette and from what research I've been able to do suggests that the Campagnolo 7sp cassette was made for a 126mm spaced hub and in 1990 Campagnolo made the switch to 8sp on the upper end groups.  There is one group, Xenon, that does show a 7sp cassette possible in a 130mm hub configuration in 1990.  Unfortunately the 90/91 catalogs that are on VeloBase.com do not show any model numbers.