Well now that I read your post more carefully I realize that your second picture is not a pic of the item you have, but rather the one you need! I foolishly assumed you had the item in pic two, and were looking for the connector on the schematic in 3 that you didn't have a picture of. I don't know what that is called or where to buy it, although I wonder if what is sold these days as a male Packard connector would fit the post?
https://www.amazon.com/Terminals-16-...%2C303&sr=1-10