The so called Quint Converter was first introduced and patented by "Titano" The late Emil Baldoni was working for the Ernest Deffner firm (Titano) and had a design for a lightweight converter system that could be used with a standard Stradella bass. The late Palmer & Hughes
were very interested in the design and the 3 of them traveled to Italy to perfect the system. This design was originally called the
Palmer & Hughes Convertor. When the patent's ran out other accordion makers offered it and It's now the most popular converter bass
system.
This book might give you a start --
This system uses a standard 120 bass stradella that with a switch converts the bass keyboard with 3 Octaves of single notes.
It mimics a C system treble keyboard when looked at in a mirror.
This convertor system has a different interior reed placement and special slides that allows the use of the standard 120 bass
to convert. The system is made of aluminum and adds little weight to the accordion. C system Button box players take to it easily as
it's their treble buttons in reverse.
That Titano Grand you have switches back and forth from standard stradella & convertor (YOU HAVE BOTH) Titano offered the
converter option on all models of student, semi-pro and pro models they made.
At the time all Titano's were made by Victoria of Italy and they also shared the patent.