They will probably fit. What they fit like is a different matter.
Check the inner bore of the wheel. If it's 58.1 mm then that's good. If the wheel has a smaller bore then it won't fit. If it has a bigger bore, it needs a spigot ring to get it to 58.1mm.. that's the size of the 155 hub.
The holes on the wheel will be 98PCD.. Fiat/Alfa uses this size om almost everything. Did the 75 come with a 5-stud wheel option on the 3.0ltr (like the 164)? Obviously you need 4 hole wheels as the 155 has 4-hole hubs.
The wheel offset is likely to be the biggest issue as 75 is Rear Wheel Drive and the offset is usually way different. On the wheels should be stamped "ET..." with a number. That's the offset. 155 likes an offset of around 35mm so if the 75 wheels are within 2 or 3mm then they'll be fine. Any more than that and they might stick out too far and foul either the suspension or the wheel arch. The difference is in mm so you can gauge the likely impact (pun! )
Appearance is another more subjective thing.. RWD usually appear more "dished" and may look strange on the 155.. but you'll have to decide that.