I happen to own a smaller Case tractor, and I know what you mean. Mice had done some damage to a wire and I could not identify the actual connector (turned out to be a Deutsch). I went to the dealer (it helps if you buy other stuff too) and spoke with maintenance -- not parts. We went out to the field truck and started looking at some of the pins for connectors. Found a match. Once I knew it was a Deutsch, the rest was downhill.
Note: Your situation is not unique. No one, except maybe CNH, wants to replace a whole harness for a screwed up pin or connecting wire. The service truck is equipped for doing exactly what you are trying to do. The pins are not in the catalog, but if you have the name for the harness, it might help.
Just looking at your picture, it might be a 0.156-pitch connector. Resembles Molex, but the pins look slightly tapered so it may be another brand. Anyway, that size or its metric close equivalent might fit.
John