Just to follow up on this for anyone else who requires the info. Jessops currently £69 for the 360AF.
This flash is badged under a number of different guises:
Soligor DG-420DZ, Sakar 952AF/SON, Dörr DAF-42, Vivitar DF400MZ, Bower SFD926, (Practica) Exacta DPZ-38AF, Also may be Opteka EF600DG Super.
and finally success at TUMAX DPT386FZ !!
found a download of the manual here: http://www.icorpandtumax.com/download.php
Apparently this chinese flash is supposed to be Gn42 but 36 is nearer the mark and hence the Jessops being Gn36.
Also not a bad flash but mine has a minor fault in it occasionaly locks the powerflash motor at the 24mm setting.