In regards to the Gepard turret, the numbers in service in the 1980s-1990s were roughly the following: -
West Germany 377
Belgium 55
the Netherlands 95
There are also other off-the-shelf turrets that could have been purchased (like the Gepard turret, these systems were designed to be fitted to tank hulls).
Marconi Marksman
link 1 link 2 link 3
OTO-Melara Otomatic
link 1 (no pics but has links to images) link 2