In MM7, there are artifacts, relics, and "Speciality Items". The first two are similar to the artifacts & relics in MM6, but the rules for getting them may be different. According to my lists, Hareck's Leather is a relic. I've had games with 2 (or possibly 3) sets of Hermes' Sandals; this is a so-called Speciality Item. I do not know how these Specialities differ from artifacts & relics. The only difference I can find is they are found in specific locations.
This isn't really much help in answering your query, but yes, this sort of thing has happened before.
