Only en_US-demo.sql needed update of the 2 core. It was done by moving 2017 to 2018 (search and replace). Then creating a new year 2019-01-01 to 2019-12-31. And setting the Company to this year. Then a couple of transactions were made.
This is all we can do. Remember things are very close mingled in the database. But this is good enough.
The en_US-new.sql was ok as is. The fiscal year was set to 2018-01-01 to 2018-12-31. I think this is ok, for when you start a new company you will often make an opening balance on the end of 2018. And then create whatever new fiscal year you need.
All the other COAs from the repo only needs a new fiscal year, I guess.
But Janusz will do some adjustments to the 2 core COA's due to SQL security injections. And of course also to the repo COAs.
The new en_US-demo.sql has been committed to repo. Can be downloaded here if needed.