Yeah they were all over the Province. Albert Bridge, Girdwood, the Mill, Ballykelly, Londonderry.... and I think that at one point the whole franchise was owned by one Choggie.
Before that they were in Cyprus and Singapore, Scotland and Germany. In fact whereever the British Army was to be found But as far as I remember, in the Province they had to bring in their supplies themselves from outside the wire and hence had to brave the run in and out.
IIRC a couple were shot by the Provos for their troubles. At that time in Northern Ireland they must have stood out like a sore thumb.
Tbh I can't say I ever grew to the Naafi and their mostly empty shelfs.