Thank you so much for your suggestion! I didn't use Revo, but this did the trick:
https://support.microsoft.com/en-us/...led-or-removed
Apparently I was so fixated on repairing/swapping out the broken files that it didn't cross my mind to search for "broken install removal". When I checked out Revo I was thinking that Windows could probably do this stuff by itself - and it can. One quick search, found it instantly, took two minutes to remove and reinstall Eucon... took me more than a week to figure that out. I am getting old :)