Apologies for lifting this one back up, but I thought the OP might appreciate some details from the Filton Aviation Archive. Your excellent glass colour slide is indeed of a Bristol Engines Olympus Vulcan flying test bed, but not for the Concorde Olympus 593 engine. The one in your pic is XA894, the FTB for the Olympus 22R engine, destined for the TSR2. This FTB was destroyed in a ground-running fire during December 1962, just weeks after its appearance at that year’s SBAC Farnborough Air Show. The successor FTB for the Concorde engine was Vulcan XA903, which was in use from 1966-71, after which it had a further few years as an FTB for the RB199 (MRCA/Tornado) programme, between 1972-9. I believe XA903 still (partially) exists in the form of its cockpit, in a private collection at Stranraer.

Ned