Mizter T wrote:

With regards to Oyster cards, most NR stations don't issue them, though
a few do. There's a list in the TfL Fares leaflet (link below), but I
believe that there are more NR stations than on that list that now
dabble in Oyster.

Now here's the toughie - where can you get NR extension tickets on top of
travelcards on Oyster? I sometimes have to pop beyond Zone 6 in south
London.