Congratulations on your new acquisition, Marc.
It is most likely an early model proofed in July 1968 (768); at a later stage Mauser changed the dating system and went to a two-letter code for identifying the production/proofing year. Such models were marketed as Mauser 66 Model Europa; one can immediately spot them because of their metallic rear sight (later models were plastic and had a Lyman look) and of their safety (later models from 66S have a side safety that is to be pushed forward, on the rear right side of the bolt).
Louis