Speciale build consistency?

I’m looking for hardware - nuts and bolts and finding that the parts catalog/diagram doesn’t have parts that fit the car properly - often screws are the wrong length or clips are of a slightly different size than factory. Are Speciale’s built on an assembly line? How consistent are cars from one VIN to another?

is the parts catalog accurate for Speciale or even Italia in general? Or do you have to just have a grab bag of parts from ie McMaster to find one that fits?

 

Local Ferrari dealer parts catalog which looks exactly like the catalog at scuderiaparts