George Jackson Churchward designed the 2-8-0 heavy freight locomotive in 1903 as locomotive 97 and 2873 was one of the last having been built in 1919 as works number 2779.  2873 is one of only seven examples that survive.
2873, like the other survivors of the class, was sent to Dia Woodhams scrapyard in Barry, South Wales, for breaking.  Fortunately 2873 didn't succumb to the cutter's torch and was purchased by Dumbleton Hall Preservation Limited to provide the boiler and spare wheels for 3803 because, at the time, re-tyring locomotives wasn't practical.
With the passage of time circumstances have changed and it is possible again to build whole steam locomotives (witness A1 Peppercorn 60163 “Tornado” and the Great Western Society's “County of Glamorgan” project) so 2873 is now unlikely to be broken up. Also South Devon Railway Engineering have a thriving business re-tyring locomotives so it is now quicker to re-tyre 3803 than make the wheels on 2873 fit.
2873 is an original version of Churchward's 2-8-0 with inside steam pipes rather than the C.B. Collet 2884 version of which 3803 is an example which has external steam pipes like “Dumbleton Hall” and 5526.
The coupling rods from 2873 are now on 2807, the oldest surviving GWR standard locomotive which has been restored to service on the Gloucestershire Warwickshire Railway at Toddington.
At the moment the plans for 2873 are in their early stages and nothing is final.  We do however need a boiler...

On the 4th February 2022 it was announced that 2873 and 3803 had been sold to the Dartmouth Steam Railway; their original destination before the then Dart Valley Railway split the business and sold the Ashburton Branch to the South Devon Railway.