The medallion was issued in 1919, and was made by Fattorini & Sons, of Bradford.
http://1914-1918.invisionzone.com/forums/topic/173218-ww1-military-motors-1916-set-x-50-cards/?do=findComment&comment=2024511
This is a rare WW1 medallion, which was commissioned and presented by the Auxiliary Omnibus Companies' Association to London bus drivers who served on the Western Front with their buses.
The medallion was issued in 1919, and was made by Fattorini & Sons, of Bradford.
http://1914-1918.invisionzone.com/forums/topic/173218-ww1-military-motors-1916-set-x-50-cards/?do=findComment&comment=2024511