Complex sentence: Petillo helped design and set up the factory located in Neptune and proceeded to BUILD the First Fingerboard Machine that cut the slots of the Fingerboards to Petillo's Trade Secret Scales with perfect intonation were kept in a safe by Dennis Berardi at the Neptune Factory.
Split into simpler sentences: Petillo helped design and set up the factory located in Neptune and proceeded to build the first Fingerboard Machine that cut the slots in the fingerboards for Petillo's Trade Secret Scales with perfect intonation. These designs were kept in a safe by Dennis Berardi at the Neptune Factory.