
That mail compartment on this coach reminds me about the changes that have taken place regarding the distribution of the Royal Mail.
The stage coaches of yore ceased with the last of them running in 1850, after the railways had taken their business, including the Royal Mail. Indeed it was in 1830 that the first Mail was carried by train on the Manchester and Liverpool Railway that had opened that year. This became a general method of transportation of the Royal Mail with an Act of Parliament in 1838.
Very quickly the travelling post office - TPO's -, with special coaches built, but the first one was no more than an adapted horse box, were used from January 1938 on the Grand Junction Railway.
On the GJR they also used for the first time an apparatus designed by Nathaniel Wordsell that dropped and picked up Mail whilst the train continued to travel.

This became a familiar sight on the railways, and the best film I can recommend for seeing all this apparatus and the TPO in action is
Night Mail , a 1936 documentary on this great process.
If you do not want to buy your personal copy, as usual this is available on Youtube:
Part 1:
http://www.youtube.com/watch?v=-WO7JxYlhOMPart 2:
http://www.youtube.com/watch?v=1pQJzZDIQTsNote this film contains the wonderful much celebrated poem,
This Is The Night Mail by W.H. Auden, and with music by Benjamin Britten:
http://www.youtube.com/watch?v=zmciuKsBOi0So with the scrapping of the TPO on trains from 4th January 2004, the Royal Mail went back to being transported in the way it had on stage coaches; by road!