Mario Maccaferri worked for Selmer for approximately two years and by his estimation produced 150 to 200 guitars.  Many of the innovations incorporated into the Selmer-Maccaferri models were ideas that he had been working on for at least ten years prior.  The exact date he left Selmer is unclear.  The exact models he worked on is not completely clear.  In an interview with George Gruhn he only took credit for four models.  Francois Charle and other attribute a total of six models to Maccaferri.

What is a clear is that the ultimate goal for the Selmer Maccaferri line of guitars was projection of sound.  The ability to project un amplified in large concert halls or over the brass instruments of a jazz band.