Following Tiny's suggestion, I found the connector in question;
https://www.store.ynzyesterdaysparts.com/gm-twist-lock-inline-connector.htmlRoadrunner, get one of these connectors, connect the wire shown from your harness to the wire that comes out of the steering mast (seen in your photo), hook up the wires to your horn that you said were cut, and see if your horn works! That steering mast wire goes up the mast to the horn button where it grounds the circuit on the steering shaft.
Kent