Convert from shaftment [ancient] to braccio [Italy]

Unit Definition (shaftment [ancient])
A shaftment, when used as a unit of length, is usually six inches or two palms, i.e. 15.24 cm (for the international inch). It is thought to be the distance from the tip of the outstretched thumb to the other side of the palm.In English this unit has mostly fallen out of use, as do others based on the human arm: digit (1/8 shaftment), finger (7/48 shaftment), palm (½ shaftment) hand (2/3 shaftment), span (1½ shaftments), cubit (3 shaftments) and ell (7½ shaftments).

Unit Definition (braccio [Italy])
The Braccio is a traditional Italian measurement of length. The word means "arm", and a Braccio is approximately equal to the length of a man's arm, about 27 or 28 inches (68-71 centimeters). In modern times, the Braccio has become an informal metric unit of exactly 70 centimeters (about 27.56 inches), which is the same as the Arm Length unit.