The Quattromini collection can be found here and the information I have found is below
Quattromini designers were made up of Guido Quattromini, Umberto Berti and Gino Berti, all listed as British subjects. They traded as F. and B. Sales and were based at 127 Caledonian Road, London N1 (now N1 NRG), just down the road from Egisto Carli
Umberto married Ms. Aurelia Sozzi in Holborn in June 1945. Umberto (Vittorio Emanuele) Berti was naturalised on 3rd October 1949 (see here). They had a son, Renato O.N. Berti who was born March 1946 in Hitchin.
There is a record of Guido R G Quattromini being born in March 1917. He married in September 1959 to a Ms. Ada Altigieri. Paola E. Quattromini was born September 1961.
There is no record of Gino Berti, but there is of a Gina Berti who was born September 1937, this would mean she was ~20 when she was in the company, so possible?? She then married in Fulham in September 1955 to a Mr. Beschizza.