LibreOffice source: https://git.libreoffice.org/core/+/e07ef10cc0d8201e5ece8e4d8b7d85a452964dc5
Qt source: https://github.com/Allotropia/qt5/tree/3d440b7787f9b5ba15e5f8bcd7aef39b388f94fa
Build scripts and patches: /licenses/office-build-source.tar.gz
Exact revisions and reproducible build instructions are included in that archive.