I am also interested in the answer to this, but unfortunately I don't have much advice to offer. My local setup contains manually inserted rows as well. I tried to use loader/pglister_sync.py as a bit of a guide. The Django admin interface also helped a little bit (for example with list creation), but in the end I had to construct queries for the remaining pieces.
Are you able to visit all the pages for inserted data? Especially this one => /message-id/id_of_thread/
If yes, could you please dump your database entries to json and share it with the community?
I also tried inserting but something is there which I am missing and hence getting an error on accessing this page.
And it's great if you could summarize the steps of initialization.
