Thrilling forum

Clandestino a Trieste (1951) credited as Production supervisor. IMDb says he should also appear. I didn't find him but my copy wasn't great so I may have missed him.

Totò, Peppino e le fanatiche (1958) as Mental patient

Il ricatto di un padre (1957) credited, as Member of the board of directors

I misteri di Parigi (1957) as One of the old beggars

Retroscena (1939) as Theater patron. Earliest discovery so far!

Follie per l'opera (1948) credited, as Saboteur

Il cavaliere del castello maledetto (1959) as Wedding guest

Ballerine (1936) as Man at the ballet.

Hard to be absolutely sure as the images are slightly out of focus, due to him continuing to walk throughout the scene, but I'm pretty confident that it's Gino and would call it a probable rather than uncertain identification. This is Gino's earliest role yet by 3 years.

Enrico Caruso - Leggenda di una voce (1951) as Excited man backstage, after the closing performance

Carne de horca (Il terrore dell'Andalusia) (1953) as One of Lucero's men.

Gino is not credited in the lengthy cast list in the Spanish version, but I suspect he may be credited in the Italian version, though, as he is one of only a handful of Italian actors in this predominantly Spanish production.