A perfect example of the beauty of Alfa part numbering system (why Fiat changed it is beyond me).
In the Alfa numbering system, the first three digits designate the chassis series for which a part was originally design or fitted to. The 4th and 5th digits are the car model within that series and the 6th and 7th digits are the parts group number.
So part number 1170105..... would break down as a 117 series chassis (Euro Alfetta), model 01 (Alfetta 2.0) and 05 is the parts group for the ignition starting and charging systems.
Part number 1161213..... is some sort of gearbox plate for a 116 series Alfetta.