It seems like you could do it more easily, include all recent additions, and have faster search responses:
1. Mirror the current gutenberg archive (e.g. rsync -av --del aleph.gutenberg.org::gutenberg gutenberg)
2. Install recoll-webui from https://www.lesbonscomptes.com/recoll/pages/recoll-webui-ins... or using docker-recoll-webui: https://github.com/sunde41/recoll
3. Run the recoll indexer
4. Each week, repeat steps #1 and #3