Radiator fan switch SOHC, DOHC- with wire connector is #4424393, but expensive- Use #4318331 without the wire, and rig a quick pigtail for it.
Early 124 (or later cars retrofitted with stat in head) can use a standard 180 degree Chevrolet thermostat, such as Stant 13308 from the parts house- Also, early-style thermostats use 2 outlet gaskets, #5923392, with stat sandwiched in between
Radiator cap, SOHC, DOHC- Fiat no longer supplies original style radiator caps- short cap is #994057, taller cap (about 1") is 4256227. - Fiat will sell you an aftermarket European cap- #994057 can also use a standard Domestic cap such as Stant R29.
DOHC Heater Hoses have some common replacements as well.