<<Is their hope in "fixing it" simply, or is the only option removing
the dash and replacing the whole thing?>>

Jon,

You win the cupie doll.

Now is the time for all good men to come to the aid of their front
heater motor.

This means you have to yank the dash and replace the motor.

No two way's around it.

Unless of course you want to try the "spray the oil into the air intake"
mambo, ala Choo-Choo Charley Inc.

( Don't do this, I was only kidding )

Replace the motor.