27005 was the first main line diesel purchased by the SRPS, late in 1987. It was acquired from Glasgow Works with the aid of a grant made by the then Royal Scottish Musuem National Fund for Acquisitions.The loco had been withdrawn from Eastfield depot in July 1987 with nothing more than a triple pump defect. One of the first jobs undertaken by MC Metals was to remove the residual blue asbestos from the handrail areas in both cabs. Movement from Glasgow to the SRPS base at Falkirk took place by rail in February 1988, where it was returned to working order.

In March 1988, it then moved on to the Bo'ness and Kinneil Railway by road and went straight into service.Restoration to the original BR Green livery was fairly drawn out, and was eventually completed by Summer 1989. However, at the SRPS Diesel weekend in September 1989, the loco developed an earth fault in the main generator. This had to be removed and sent to a specialist electrical contractor for repair to one of the field windings. The loco returned to service in March 1990.Since then, it has given 10 years reliable service, until being taken out of use in September 2000 for major body repairs, having suffered badly from corrosion. It received two livery variations in that time, the first being full yellow ends with the green livery, as carried by some locos in the early 70's, and then a repaint into BR Blue livery in 1998.

This was to recreate the sight of two blue 27's, and it was adorned with Inverness 'stag' emblems. In July 2000 it travelled South to the East Lancashire Railway and took part in their 'diesel week'.The loco is currently out of service awaiting repairs for corrosion and a top-end engine overhaul. It is now in the Scottish Railway Exhibition Building as the sole representative of modern traction in the display.