It would be a fun one that’s for sure. I would favour Naz, just a far better athlete and Fenech is extremely hittable. Would be fun as the fight goes on, with Jeffs durability and Naz’s power.
If Fenech was wise enough to be defensively minded over first few rounds I think he takes over and wins. Naz struggled to generate his power when faced with someone who is constantly pressuring him.