Agree with Hamster campag didnt do 11 25. your best bet is to go for a Miche Primato 8 speed campag compatible cassette normally around £30 new in following ratios
12-21: 12|13|14|15|16|17|19|21
12-23: 12|13|14|15|17|19|21|23
13-21: 13|14|15|16|17|18|19|21
13-23: 13|14|15|16|17|19|21|23
13-26: 13|14|15|16|18|20|23|26
13-28: 13|14|15|17|19|21|24|28
14-23: 14|15|16|17|18|19|21|23
15-22: 15|16|17|18|19|20|21|22
15-23: 15|16|17|18|19|20|21|23
16-23: 16|17|18|19|20|21|22|23
Just watch it with the 28T ones - works fine if you have a long drop on the derailleur hanger, not well with a short drop frame. In that case, fit a mech dropper (£2ish from eBay).