Thrilling forum

Parole e sangue (1982 TV miniseries) episodes 1, 2 & 3/3, credited as Alessandroni.
Big role here for Roberto in this crime miniserie.
Episode 1 Episode 2 Episode 3

Paradiso infernale (1988) aka. Natura contro, credited but not found.
This is strange because also Sal Borgese, who is credited could not be found after multiple searches by Peplum Paradise or Stuntman Mike.

Altrimenti ci arrabbiamo (1974) credited as Henchman (the one on the left)

A forza di sberle (1974) aka. Hamama giren terler, as Chakiris.
Italian-Turkish action comedy movie, filmed in Turkey.
Unfortunately there were no end credits named in the Turkish copy i found, so he could be credited in another one.

Un dollaro bucato (1965), as James henchman

Per pochi dollari ancora (1966), credited as "Robert Alexander", as Riggs henchman

Anche gli angeli tirano di destro (1974), credited, as Maloney henchman

Il sogno di Zorro (1975) as Ruarte soldier, not credited.

T'ammazzo...raccomandati a Dio (1968) as Hartmann henchman, not credited.

Carogne si nasce (1968) as Street fighter, not credited.