Complex sentence: The first official name the team received was "The Builders" ("Stroitel") in 1969, although, the team already existed and participated in the regional competitions since 1964, but without a real name.
Split into simpler sentences: The first official name, the team had received, was "The Builders" ("Stroitel"). It happened in 1969, although, the team already existed and participated in the regional competitions since 1964, but without a real name.