Nacho,
That is what I am afraid of (that OEM rebuild parts won't work for the high-output alternator).
I wouldn't say that in the diodes bank case. Definitelly brushes and isolators are the same... Stator I don't think so of course. Rotor dunno.
Now, about the SUDDENLY working alternator... check the field brushes assemblies. Fuel line runs at a side of the alternator and maybe playing around, the brushes were moved/relocated. We are talking about an 8 years alternator? but... how many miles or how much time you have run the engine ?
Once I got a melted isolator and brush inserted in it, making to loose the contact with rotor trace ( I have a pic of that... somewhere )
Editing
Found the pic. Somehow the brush could got heat enough being able to melt the isolator and get inserted into the plastic
