Unusual with the 'flat plate' across the top of the engine. I dont think its a single engined jobbie because the bodywork would follow the exhaust profile, so that makes me think its a side by side installation. Now why would there be a flat across the top unless the engines where mounted just uderneath the wing instead of in pods.
Ok, yup...errrrrr....Comet ?, no, that has a curvy profile...Victor, nope hang on a minute, I reckon its an Olympus from Concorde