Complex sentence: Akram's previous before 60's record shows that he participated in around 280 major wrestling events during the 1950's, some of which remained alive in the memories of people who watched him wrestle for a long time.
Split into simpler sentences: Akram's previous record shows that he participated in around 280 major wrestling events during the 50's. Some of which remained alive in the memories of people who watched him wrestle for a long time.