Trans-Atlantic telephone calls could not be made in 1925.
Filter-tipped cigarettes did not exist in 1925.
The expression "Up the duff" was not in use in 1925.
(At 55:34) - When Tommy holsters his M1911, a Kydex shoulder holster is clearly visible under his coat. Kydex was not invented until 1965 - 40 years after this episode takes place.
Luca touches his right shoulder first while making the sign of the cross. As a Catholic, he would touch the left first.