25279 is one of 20 preserved Class 25s from an original fleet of 327 locos. Built as D7629, the loco is one of the final batch, designated Class 25/3, and was constructed by Beyer Peacock in Manchester. As built, D7629 was Vacuum braked only and fitted with a Steam Heat Boiler. During conversion to Dual Brakes in 1969 the boiler was removed and the boiler room used to house two compressors.

Delivered new to Tinsley depot on September 7th 1965, D7629 had a varied 21 year career mostly based in the Midlands and North West of England. It gained the TOPS number 25279 at the end of January 1974 and was withdrawn on 18th March 1987.

Despite several months at Vic Berry's scrapyard from late July 1987, the loco survived and entered preservation on 19th March 1988, moving by road to the Llangollen Railway, where it remained until 1997. Thereafter it was loaned to the Chinnor and Princes Risborough Railway, then to the Gloucestershire and Warwickshire Railway, before finally ending-up at the Northampton and Lamport Railway in 1999. The locomotive was unable to return to Llangollen Railway following the line's decision to strictly limit the number of diesel locomotives based there. The combination of this and a number of accumlated faults saw the loco put up for sale in April 2000.

D7629 was sold privately to Mark Fowler, who remains the current owner, being moved to the GCR at Loughborough by road in the last week of June 2000. Extensive restoration took place at Rothley and the loco was fired up during March 2001 but it still suffered from a number of minor problems which left it confined to yards only. However by the middle of June 2001 enough had been fixed to permit a test run on June 20th that would reach beyond the confines of Rothley yard. Road tests were completed with 47117 and proved successful. D7629's GCR passebger debut was on July 14 but sadly the turbocharger seized and the loco returned to Rothley shed the next day. Repairs were made in time for D7629 to appear at the July 2001 GCR Diesel Gala.

Following bodywork attention and full repaint during the first quarter of 2021, the loco is now transformed into BR Blue livery with running number 25279, giving a taste (for the first time in preservation) of Type 2's in the 1970s and 80s.