Hey David,
Reg says (among other things), "The rear brake hanger should be curved round rod I think, not pressed from flat sheet"
I am no kind of expert on Dawes bikes, but the Galaxy I just bought on Ebay most certainly does have the flat sheet rear brake cable hanger (see photo of saddle) see the link:
http://ebay.com/
Not that having this hanger guarantees your bike is a Dawes (since other makers could certainly have used them), but hey, what do I know?
Duncan Granger
Mountville, PA