The Fasti Ecclesiae Scoticanae is a multi-volume worked originally publied in the 1800s, with a later edition around 1915, and with subsequent volumes bringing it up to date; so it is not something which an individual is likely to own - unless they are quite rich!
The best place to try is reference libraries. Most UK libraries of any size will have a set. Even my local, Wick Library, has a set in the reference department.
Gordon