Thank you JL! 
Having adjusted the V-belt on alternator and know how incredibly cramped and inaccessible it is down there so I fear trouble and swearing  

 regulator unit is equal on 1.6 and 2.2 model, I think?
Charge lamp has incidentally stopped flashing. Wonder if  an engine wash was to blame?
Others here have experienced that it has flashed after an engine wash? 
But charging has been a little low since I got the car, so I think I change the regulator anyway.