Not sure if you've received any answers since you last posted..
I have seen the passenger list.. it does appear interesting since there were 2 Molteni's on board, but they were not listed together.
If they were connected, makes you wonder why this weren't listed together... or appear to be traveling together.
You say that "Francesco came from Como, probably Villa Albese".. can you clarify the name of the town? Is there a document (on Ancestry) that says he was from "Villa ALbese" .. I wouldn't mind taking a look at it..
Look forward to your reply.