Iranian fuel oil exports trade skirts sanctions

* Thousands of tonnes sold a month via Gulf-based firms - sources * Origin sometimes disguised, specifications altered - sources * Sanctions have hit Iran's crude exports, hammering economy By Rania El Gamal DUBAI, Feb 3 (Reuters) - Iran is sidestepping Western sanctions and managing to sell hundreds of thousands of tonnes of fuel oil every month through companies based in the U.S.-allied United ...