Maybe not haggis, Nox, but certainly booming whisky exports and - given that Scotland has a North Atlantic coast while England does not - it has free access to the oil there as that area's production expands and the North Sea's dries up. Oh, and also given the hosepipe ban in lumps of England already, Scotland could happily provide England with tankersful of water...at a price, obviously!
Apart from financial services, which many claim could disappear to Geneva at a moment's notice, and some luxury goods, what does England have that anyone else wants to buy? BAe, the major manufacturer, is closing depots and sacking people by the busload.