Complex sentence: This is attributed by some luthiers and repairmen to a gradual trend of misplacing the bridge on these guitars: the same jigs for bridge placement were used throughout the history of each model's production.
Split into simpler sentences: This is attributed by some luthiers and repairmen to a gradual trend of misplacing the bridge on these guitars. Apparently, the same jigs for bridge placement were used throughout the history of each model's production.