Damn I used to buy my oil from Heltor too!
I am useless at Tors apart from Hound (when you can see the nose) Haytor and Vixen Tor, the rest of the family have climbed them all from one side of Dartmoor to the other whilst I stayed here and relaxed with a book...
(so it's no wonder I can't identify Heltor, where exactly is it then?)