Car won't crank, Fusible link blown

Yes!!

Don't forget, tho, that there could be a short right there in the ready-to-run set up

When you get to troubleshoot it, do this:

Scare up a tail lamp or backup lamp and socket, or a headlight. Wire that in series with the battery ground. This will allow you to do some testing while the lamp acts as a limiter

Since you think activating the key brought on "the smoke" I would check out the ignition "run" circuit. This would include all the wiring under the hood served by the dark blue "run" circuit

It might also be something in the cluster. Look for blown fuses you missed which would be a clue. If this is an UNFUSED problem, this includes the ammeter and wiring, headlights (only) circuit, and the "hot" buss in the fuse panel. None of those are switched by the key, but all are unfused. Also a shorted alternator

To check the key switched accessory buss, pull all the fuses (one at a time) and see if the short disappears.

Have you added anything to the "run" circuit that could have shorted/ failed? Stereo amp? Radio? Tach?

I would take a good look at the harness going to the alternator, regulator, and ignition system wiring.