Thanks for your reply. Unfortunately that doesn't seem to work.
If I take for example a German production movie "Keinohrhasen" I
find these entries
tt0960790 10 Keinohrhasen \N \N original \N 1
...
tt0960790 19 Keinohrhasen DE \N imdbDisplay \N 0
...
tt0960790 21 Keinohrhasen EC \N imdbDisplay \N 0
i.e. that the record with the "original" flag shows no production
country ("\N"), and neither of the other two is flagged original.
Inspecting other entries (e.g. "Miami Vice") it's similar; all the
entries marked with 1 ("original") seem to show a region of "\N".
Janis