So this is the info I got from the police officer that just left. An office will be established near Khao Kradong for 90 days reports and change of address. Next month... wait and see!
He was not from Immigration police, he had a badge labelled ' Investigation Police', haven't seen that one before.
He also told me that he had arrested 20 people this year 'from Africa' that had been working scams, mainly to do with marriage extensions. That may explain why these visits are becoming more frequent, although if I understand correctly, in my case at least this will happen only every five years. (I am very obviously married). He asked me twice if I was doing farm work and also if I was healthy, which was a new one for me.
A nice, correct guy, he told me I could report this info here.
Petrol money was put in an envelope, I suppose that's fair enough.