I managed to acquire a number of early maps in a recent auction of some material from the Bath Postal Museum (sadly closed).  The earliest maps I acquired are strip maps drawn by John Ogilby published in 1675 & 1698, this first being of a portion of the London to Bristol road, going from London to Marlborough.

The envelope below, sent from Taunton to Ashill, Ilminster in June 1974 has a bisected 2p stamp used to make up the 3p second class rate.

This postcard from October 1919 has a previously unknown Climax rubber cancel for "BASON BRIDGE / BRIDGWATER".  The post office in Bason Bridge had closed in 1916 and was thought to re-open in 1920, but this postcard indicates that it opened somewhat earlier. 

Below is a Red Cross prisoner of war postcard from Doberitz POW camp sent to London and redirected via Kent to Taunton, arriving in April 1917.  The card is signed "Bdsm D. Hall", perhaps Bandsman Hall ?  The card is requesting soap and toilet necessaries in the next Red Cross parcel.