Hi there, I am the original thread poster. Thank you all for your comments.
There were no crystal balls present. I appreciate that nobody has a full handle on what will happen post brexit, but there are already some things which are obvious. In order to be able to adopt a possible new European immigration status (mirroring the already agreed settled status which Britain has decided to create) or simply to have a valid immigration status post brexit, it is helpful (your lifejacket) to already be registered (a lot of Brits in Spain are not, which is understandable as we have had the right to be here for the last 25 years and very little hassle from authorities for not being).
There are two types of registered status. Resident and permanent resident. Permanent resident is obviously more desirable if you wish to continue liing in Spain post brexit. The advice I have had is to obtain this. This is a more complicated status to obtain for some of us than for others. The advice I received was with reference to this (which changes from region to region.)
So, if you have no worries, and are avoiding the crystal ball while you wait for the axe to fall, send me some more of yer blithe comments. If you have a few concerns, let me know, I might be able to point you in the right direction for some sounds advice.
Knowit.