Somerset & Bristol Postal History

Wiveliscombe was made a Railway Sub-Office (R.S.O.) in October 1874, and remained one until 1905 when the "R.S.O." terminology was abandoned, when it became a Sub-Office/Post Town.

The "WIVELISCOMBE R.S.O. / SOMERSET" cancel remained in use after 1905 (see the first item below).
 It was eventually replaced with a "WIVELISCOMBE - S.O. / SOMERSET" double-circle, double-arc cancel - here are two examples used in 1914 and 1915.
 In November 1919 Wiveliscombe came under Taunton again - here is a "WIVELISCOMBE / TAUNTON.SOM" cancel from 1942.

A couple of sheets, one with cancels for Bath Station Office, the other for "BATH S.O" which I am assuming is Bath Sorting Office - is this correct ?  Then, other towns have "R.S.O." - is that Railway Sorting Office ??







This leads on to another question I'm looking for answers to:  what role did the railways play in the Post Office, and how did this change things following the railway mania in the 1840s ?