The cast number you are looking at is the part number for the "front cover", not the entire pump. You see them for sale incorrectly stating that or the rear plate cast number is the entire pump part number.
FWIW Saginaw sold those pumps to Ford. Ferrari, and other manufacturers, similar to their power steering pumps.
Per the AIM, they used 3 pumps in 67, and the pump assembly numbers were 5696468 for the L30 and L48, 74800308 for the L35, and everything else used the 5696104.
The front cover cast number on the L30/48 5696468 pump is 5696582. You can also tell that pump by the rear tubes. In your AIM look at UPC K19 Sheet A10 and you can better see how the tube that went to the air cleaner base has a bend. I think all the other pumps had three straight tubes. If you look for a pump with a front cover 5696582, that one rear tube with a bend, and a 4 bolt pulley flange, and acceptable date code range, you should be good.
Does your third picture in your first post show a pump with a 5696582 front cover? On a side note, is your oil fill tube painted black or chrome?
