I finally got tired of waiting for a solution to the upgrade / rollback issue with build 26058, so I attempted a clean install with the ISO on USB. Well, it worked, I got all the way through the install and the system is up and running.
A couple of issues with 26058 include the weather applet does not appear on the lock screen regardless of setting to that effect; also I keep getting prompted to sign in with my Windows PIN (not sure how to remedy this).
PS - I figured out how to turn off the PIN.