Not unusual for co-workers in the gun trade to part and the employee open his own business. It was commonplace in the English gun trade. No reason for it to be different in the Italian. Indeed, Daniele worked in a small shop from the age of 14, learning the trade. At age 18 he started his own business and started to make guns under his own name.
He was partnered with Ivo Fabrii for about a year, when Fabrii left and started his own business. Even such a notable as Ennio Mattarelli was working with the two when the first Perazzi competition gun was designed and born. Mattarelli took it to the '64 Olympics in Tokyo and set a new world record and took the gold in that event.
It is healthy for apprentices to work their way up in the business and eventually leave for greener pastures, IMO, though it must cause the business' owner some consternation. Without that, the wonderful Fabrii guns would not be.
SRH