This magnificently oily Campagnolo catalogue 17 has a copyright date of 1974, and is generally considered to date from late 1974, describing the range for model year 1975.
Handily, this particular example is in French - which lends it a certain je ne sais quoi.
Amongst much else, it describes a classic line-up of derailleurs:
Strangely, there was no mention of the unlovely Campagnolo Velox (2250) and Campagnolo Gran Turismo (2270). These two gems appeared in the earlier Supplement to the Cycle Catalogue No. 16 and in the later Catalog 17a, but were absent here - perhaps they were an embarrassment best kept hidden.