Took Opaque’s advice and reinstalled uno-libs 3. Then, I attempted sudo apt install libreoffice, which resulted in a big long display that ended as follows:
"Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)
Command ‘libreoffice’ not found, but can be installed with:
sudo snap install libreoffice"
which I did. Now I have libreoffice working, nice new 188.8.131.52 version. Clearly there is also some issue with dpkg, but I won’t worry about that. Thanks for assistance of Opaque and Ratslinger.