Thanks for the welcome Voyager!
you are correct in you guess on the model number of the base cabinet it is CHSUB672F

the far left board in my bottom cabinet is called a B3CAU1F L9 1074 LNZ296 this number is printed on a white sticker with a bar code to its left .It is connected to the card to its right via 2 ribbon cables .This board is called a B3CBU1F L9 1094 LNZ297 this number is also printed on a white sticker with a bar code to its left .Hope this helps!!

aalleexx