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:
/tmp/apt-dpkg-install-BGXK4R/07-libreoffice-common_1%3a6.0.7-0ubuntu0.18.04.10_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
rjs@RSBK:~$ libreoffice
Command ‘libreoffice’ not found, but can be installed with:
sudo snap install libreoffice"
which I did. Now I have libreoffice working, nice new 6.3.2.2 version. Clearly there is also some issue with dpkg, but I won’t worry about that. Thanks for assistance of Opaque and Ratslinger.