quadrajet question

[mjck5]

i have a question for all you quadra jet experts out there, i have deciphered most of the markings on my carb its a 17080204 and after that its 3529cpm, i figured out the 3529 is the date code it was made but what is the cpm stand for? also on the front of the carb is a grid with with A-L on the left going down and punch marks on different spots in the grid, anyone know what these stand for?

 

[bucket]

The grid sounds like a casting date code too? Letters represent the month of the year and the columns next to that represent the year of manufacture. Maybe?