Thank you so much Joe. If Hugo ever has a Mount Rushmore, I’m sure your face will be on it!
So much for trusting bep’s code without examining it carefully. He forgot the closing quotation mark in the code I copied. 
https://discourse.gohugo.io/t/using-resources-postprocess-and-resources-fingerprint-together/28909/
Thanks also for clarifying that if you use mounts (at all) then you need to specify everything. I thought that “assets” was the assets directory by default and did not realize ALL of those default folders need to be specified as mounts. Thanks for the link to the applicable documentation!
Appreciate the prompt answer!