I thought if you look at the FIA Homologation for the GTA and the FIA rules of the period, various items changed like brakes from Dunlop to ATE, so you can work out from the year the car was made and the FIA documents what components it was initially made with, then add the commentary who did what and when later.
All 848 GTAs were post Dunlop, so ATE equipped anyway. FIA docuuments won't tell you what the car was made with anyway, they will only show what was homolgated for FIA class use from a given date. Not all cars had all homologated parts & also as we well know, Alfa is certainly known for parts bin production line runs, as in the nearest line may have run out of item brand "A" while line the other line continues with item "A" until the bin is empty. This is presumably how some 'newer' chassis numbers have superceded items when an 'older' chassis number has the update. I'm sure this must only span days or a week at most.