Found my dads original 1971 duster!

Here is the wire that was cut and jumped to the battery

View attachment 1716268399
Steering Column connector.
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red wire is J1-12R. Your buddy left enough room for a decent splice. A lot of the cable bundles in there do not have much slack, but that one probably has enough to do like you planned and not have stress or rubbing.

Black wire with ring terminal. Where does that come from? Is that the other end of the steering column ground?

Side note on terminology:
"Battery" is used for all wires that connect to the battery positive. A more precise term would by Power In, because the power can come from the alternator or the battery, and usually its the alternator. However everyone calls it battery power.
"12 Volt" same concept. It's called a 12 volt system even though normally it runs about 14 volts. It's common usage is fine but when troubleshooting power issues sometimes its really important to be precise about the voltage measurement.
"Alternator" gage. Wish I knew Chrysler labeled ammeters this way. It could be because the alternator was there name for the new (1960) A/C generator and wanted to promote it. If the engine is running and the battery is discharging, the charging system isn't working. So in that a way, its an alternator gage.