308 rotor replacement?

That number comes up as a European single distributor rotor. A very different part.

Those rotors look pretty old. What goes wrong with them is with age the insulating properties of the plastic break down and the spark bleeds right through them to the distributor shaft.Your choice but to me they look like they have done their job.

You need to look up a rotor for a US dual distributor car.

 

I was going to give you the correct number but decided not to and I'll tell you why.
I have been fixing Ferraris for over 40 years. I am a mechanic, not a parts man. If I look up a wrong part as you have done here, its my fault and if I order it thats also my fault.

If on the other hand I use a good knowledgeable parts guy like Daniel the chances of getting the right part are better and if you don't its on him.
The old Yugoslavian mechanic I apprenticed under taught me a valuable lesson. "Dont tell the shoe maker how to make shoes.".


Take the capacitor to an electronics store if any still exist.

 

Note the new aftermarket rotors available now fit pretty darn tight too.

 

Get 124288 -- it's the later 308QV rotor that has the wider tip that makes rotor-to-cap phasing less fussy (works fine on US version carb 308 dual distributors):

https://www.ferrariparts.co.uk/part/ferrari/124288?id=87097

That capacitor doesn't seem to be shown in the 161/78 SPC for '78-'79 US 308B/S, but it might have been considered an inseparable part of the coils (like the ballast resistors that also don't have part numbers in the SPC). It is shown (item G) in the ignition wiring diagram (on page 74) in the 150/78 OM for '78-'79 US 308B/S.

 

The capacitor… to minimize radio static noise.