Olinto Gallo, who would later rename the company, started working as an apprentice around 1910–1912 (the date cannot be verified), at the peak of the development of medal engraving art in Argentina marked by the centennial of the May Revolution. Gallo was the second of three children of an Italian family.
In March 1920, Vanzo sold the company to his son Silvio and to Gallo, who renamed it Rosario's Engraving and Chiselling Workshop. Its seat was at the core of Rosario's downtown, on 936 Córdoba St.. The owners eventually decided to separate the commercial site and the workshop; the offices for the public were moved to 1328 Santa Fe St., still in the city center, while the workshop was relocated to 1055 Olivé St., in the neighborhood (barrio) of Arroyito.
Gallo gave his own name to the firm in 1934. The Olinto Gallo Workshops gained renown in their field, reaching the levels of prestigious houses in Buenos Aires.
The workshops were eventually shut down. The building turned into ruins, while machinery and products (medals, plaques, license plates) were left abandoned and uncared for. Its demolition was finally scheduled for 27 March 2006. Before that, a group of volunteers rescued a number of works, to be exhibited at the Municipal Museum of the City; and a little rests at "Ferraro, Maquinarias y Rezagos Industriales", Pte. Roca St. 3546, Rosario.