Dulverton, Dunster & Fishpond[s] (Bristol)

First here are two examples of the "DULVERTON / 187" mileage mark, from 1801 and 1815.

Here is an interesting cover from Dunster in 1827, with a boxed "No.4" receivig house handstamp and a "DUNSTER / 183" handstamp.  Dunster remained in the Taunton Fifth Clause Post until the Taunton Post was reorganised in 1828.  Because it was a 5th Clause Post and not a Penny Post the franked letter was free (it would have been subject to the 1d charge under a Penny Post).

And finally a skeleton handstamp for Fishponds, with the final "S" missing - "FISHPOND / BRISTOL" from the end of 1920.