I could well be wrong, I can picture a plastic character with ESSO scrawled acroos its chest from the Biscuit Tin but maybe it wasn't a smurf, some thing smurflike? Wannabe Smurf? Maybe it was Esso's competitor to a smurf, defienitely said ESSO on it though.
I don't remember Esso smurfs, but I do remember an Esso keyring I think my dad had, with a little man with a flame shaped head, and an all white body. I also remember, not only Olympics coins but also football coins, (world cup?) with pictures of players on one side, that went into cardboard holes. I don't think we ever got a whole set. I also remember my dad saving up coupons to get roly poly glasses from the garage, we had a couple of those, and they used to put the petrol in the car for you, my dad used to say, '£5 of four star'. That was when petrol was in gallons, not litres too, of course. Hate to think how much a gallon of petrol would be nowadays, lol!