Visible crew/equipment: During the Basketball wish, while Elliot is being interviewed by the sportscaster, you can obviously see cardboard "people" filling the stands in the background. (00:49:45)
Visible crew/equipment: In the wish where Elliot is a drug lord, when he is driving to his stables, in one side shot of the black van you can see crew members reflected in it. (00:31:10)
Visible crew/equipment: When Elliot, as a drug lord, runs to the plane and hangs off of it as it takes off, in one shot behind him you can see the whole camera dangling down. (00:34:25)
Answer: It definitely is a Montegrappa Oriental Zodiac pen, this brand has been making pens in Italy since 1912. I am not sure which of the three red pens in that collection (Oriental Zodiac) is the one seen in the movie, but given its association with the devil, my guess will be it is the Ox fountain pen.