rotary dial telephone TPO mail exchange apparatus pouches ready for TPO collection labelling bags on the TPO Travelling Post Office sign GPO Salvage Squad GPO Salvage Squad Angel of Death GPO telegram boys wartime ration books GPO sorting frames GPO postwoman WW2 postwoman WW1 sorting office WW1 sorting office early Post Office uniforms penny farthing delivery bike early post office bike? Hauteville collection times early Victorian letter box Victorian green and gold post box Royal Mail coach Mount Pleasant sorting office morse receiver old pneumatic rail car old green mail car mail rail maintenance Mail Rail tourist train inside the Mail Rail tourist train London Post Office Railway grey day in Gray's Inn Road Dulverton Mansions down Gray's Inn Road freezing in Gray's Inn Road detail at Tiverton Mansions Verulam Buildings passing Gray's Inn Gray's Inn bus stop Staple Inn, Holborn Royal Fusiliers war memorial Holborn loos St Andrew's and City Temple Prince Albert statue Smithfield Market under Holborn Viaduct