He was born Józef Bruno Winawer on March 20th 1902 (IMDb alone gives a date of April 12th 1897), in Warsaw, which was then part of the Russian Empire. His mother was Polish writer Regina Winawer and his older sister, Stanislawa, better known as silent film actress Soava Gallone, was married to Italian film director Carmine Gallone.
His known film career began in 1940 when he appeared in 4 films, 3 of which were directed by his brother-in-law, who would go on to direct him in around half the films he appeared in. He continued to work as an actor for the next 15 years, playing small character roles, seemingly calling it a day in 1955. His Wikipedia page says that he was also a theatre actor.
Giuseppe died in Rome on February 25th 1965, aged 63.
While I have not yet found any undocumented appearances, from the type of roles he played and the fact that he seems to be rather forgotten these days, I think it could be quite possible that there will be more uncredited roles to be discovered. His rather unusual appearance, buggy eyes that give him a fish-like appearance and pock-marked cheeks, should make him easy to recognise.
- Maddalena... zero in condotta .... Amilcare Bondani (credited)
- Melodie eterne .... One of Mozart's detractors (uncredited)
1941 - L'amante segreta .... Hotel desk clerk (uncredited)
1942 - Odessa in fiamme .... The Scribe (credited)
1943 - Harlem .... Sherman henchman (credited as "Varni")
- Tristi amori .... Rublo (credited)
1946 - Avanti a lui tremava tutta Roma .... The Maestro (credited)
- Eugenia Grandet .... Mr. Des Grassins (uncredited)
- Rigoletto .... Count of Ceprano (credited)
- Wielka droga .... Field hospital chief technician (credited as "Józef Winawer")
1947 - La grande strada .... role? (poster credit as "G. Varni")
1948 - Fiamme sul mare .... Matteo La Spina (credited)
1949 - Black Magic .... Boehmer (credited)
- Il Trovatore .... Old Count of Luna (credited)
1950 - La forza del destino .... The charitable pilgrim (credited)
- Taxi di notte .... Francesco, the Forenti family's majordomo (credited)
1951 - Messalina .... Pallante (credited)
1952 - E' arrivato l'accordatore .... Dinner guest (uncredited)
- Tre storie proibite .... Surgeon (uncredited)
1954 - Casa Ricordi .... Monti (credited)
1955 - Don Camillo e l'onorevole Peppone .... Christian democrat (uncredited)
- Amami, Alfredo! (1940) ANICA
- Oltre l'amore (1940) ANICA
- L'orizzonte dipinto (1941) ANICA as Clown
- Primo amore (1941) ANICA as Editor Wolkoff
- La donna del peccato (1942) ANICA
- La signorina (1942) ANICA
- Le due orfanelle (1942) ANICA as Picard
- Luisa Sanfelice (1942) ANICA
- La danza del fuoco (1943) ANICA
- Sogno d'amore (1943) IMDb
- Finalmente sì (1944) ANICA as Giuseppe
- Biraghin (1946) ANICA
- La portatrice di pane (1950) IMDb
- La grande rinuncia (1951) ANICA
- La colpa di una madre (1952) ANICA
- Wir tanzen auf dem Regenbogen (1952) ANICA
- Quo Vadis (1951) IMDb as Hairdresser. The only hairdresser that I'm aware of is the one played by Alfredo Rizzo.