65amp wiring/trouble shooting

The questions are about this 1974 Heavy Duty Alternator option with Rear Window defroster.
The wiring is different than we've seen, and there also is some question as to which alternator this car got as there is some confusion in the manuals and sales info.
see this post

it looks to be a Chrysler (as opposed to a Leece Neville).
A tag on it was originally colored and stamped with a rating or similar identifier.
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The other question was about the main wire connections:
We plainly see there are wires, at least 12 gage, going through the grommet.
It also appears that some of the standard wires were left connected. Did they operate in parallel? Or was a segment removed or cut and capped?
Those would all be good to know, especially if one needed to do dome trouble shooting, or in Mark's situation, if he wants to replace wires using bits from another harness.

See this post

Best guesses is
the standard battery feed was removed or capped inside.
one branch of the alternator output goes direct to the main splice
1688647006984.png

OR one branch of the alternator output goes direct to the heated back lite relay.
1688647381756.png

One thing that bothers me as that we haven't identified fusible links protecting the 12 gage wires.
There should be one or two blue fusible links (16 gage) to protect those wires.
If the black fusible link is really black, then its 12 gage and only protecting the 8 gage wires.