Michael Gilbert 
Paint Gold And Blood 

A young man stumbles across a conspiracy to steal an early Italian triptych in France, little realising that years later it may hold the key to his future wellbeing. Meanwhile, he deals with a matter of embezzlement of church funds not to mention the decoding of confidential information contained in Pepys writing system. All of this pales into insignificance when compared with him tackling an international art smuggling ring, with treasures being sent to South America in order to finance terrorism.