I've just had a quick scan through my old Theoben Info. Sheets from the mid/late ninties and it would appear the Fenman, Taunus, Olympus, Eliminator and SLR 98 all had the Evolution trigger as factory fitted standard. I believe the Sirrocco 2000 and the Dual Magnum also did !
It's possible there may have been a few exceptions and no doubt owners could have modified or swapped the trigger to suit their requirements along the way ?