In answer to an enquiry about National Anthem on the message list, Frans Steensma writes:
The group consisted of Rob Walker, Mick Roberts and Nick Hobbs. Matthew (guitar and electric piano) produced and joined them for a short time in December 1970.
When I asked Matthew about it, he said: Not a lot happened with the group. Nick became label manager for EMI's Harvest label (did very well) and then his own label, Automatic Records, which did nothing. No records by National Anthem were ever released.
Hope this helps something.