Enrico Gnesutta, with workshops at Via Dante, Milano, was a bicycle manufacturer who is thought to have built a limited number of motorcycles under the "Gnesutta" brand in the years 1899 to 1900.
According to AISA, "In 1899 ing. Adolfo Schlegel, Director of Officina Meccanica E. Gnesutta of Milan, built a light car, possibly fitted with a Welleyes engine." ¹
Fausto Alberti married his daughter, and Gnessuta had a senior role in his son-in-law's company. It was he who chose the company name of Sertum, the name he applied to his bicycles.
At least one source spells the name "Gnessutta".
Sources: Moto di Lombardia, AISA Associazione Italiana per la Storia dell’Automobile, et al
Notes. 1. Welleyes by Ceirano of Turin, which shortly became FIAT.
