When it was moved to the UFC section.
When I bought the 1000f ones, I was told that they were from exactly where you put them but as you say, nothing is 100% although I had no reason to question the person's information and they were very definite in their minds that they were from there.
UFCs are a great way to spend time researching and trying to find where they are from (as you know) so it would be great if somebody could put some time and effort into being productive, and useful, in helping to attribute them.