Hello! I live in Duns so got a good idea of the rally area! There are a couple of Shell garages around,theres the Eyemouth one as mentioned also one in Berwick upon tweed which is around 20mins from duns but its near Mcdonalds too if your needing a quick drive thru top up yourself!! Best bet is eyemouth though,thats the one i use!Theres also an Esso garage in coldstream which isnt too far from the Leitholm and Eccles stages and in Duns itself there is Jet and Gulf so you shouldn`t run out!!
Cheers!!