Underdash Harness bunt up

Practically speaking. Look at the wires and connection terminals. Mark which ones are damaged.
If its just a couple wires and does not involve the main splice, they can be replaced.
Main splice can be repaired too - but you want to really do a good job. Your friend may be so skilled - if so - go for it.

Most of the terminals are Packard 58, some Packard 56, and the column connector uses something like a molex.
The main feeds can be run through a grommet instead of, or in addition to, using the bulkhead connectors.
Chrysler did that for some a-bodies optioned with 59, 60 andor 65 altenators, at least some years.