Thrilling forum

Il nido del ragno (1988) credited as Polgar Moricz, the antique dealer (what's in a name)
This is an odd and very strange horror movie, made on a low budget and outdoor scenes were filmed in Hungary !
Most of the cast were unknowns except for French actress Stéphane Audran, the wife of director Claude Chabrol and William Berger
in supporting roles
A later role for Arnaldo here and as you can see at the sign of the shop, he is indeed playing the role of Polgar

Lo chiamavano Trinità (1970) as Mormon fighter.

Pretty impossible to get a clear shot of him as he is only seen briefly and is constantly moving. Identification by Rudy

Carambola, filotto... tutti in buca (1975) as Bakery and barroom brawler

La vendetta (1989) as Henchman
Only seen in a glimpse in this action movie when he is shot dead at the swimming pool
USA movie title : Getting even

Thanks to Nick for the identification !

Maciste nelle miniere del re Salomone (1964) as Guard

Ciakmull - l'uomo della vendetta (1970) as Saloon brawler
In the first picture you see clearly that it is him
identified by Nick

Continuavano a chiamarlo Trinità (1971) as Monastery brawler.

Pretty impossible to get clear shots of a lot of the stuntmen in the monastery brawl, including Arnaldo and Roberto.

I due sergenti del generale Custer (1965) as Confederate soldier the in saloon brawler

Bluff storia di truffe e di imbroglioni (1976) as Prison guard

Mal d'Africa (1990) credited as Stunt coordinator.

Arnaldo does not appear on-screen himself, but his brother Ottaviano has a small stunt part.