Wells

Here is a fairly early straight line handstamp from 1774 (there are a lot of early Wells handstamps that I do not have examples of).

Then a two-line "WELLS / S. 123" mileage mark from c.1786.  From this handstamp onwards, the Wells handstamps had an "S" or "SOMERSET" or similar to indicate it was the Wells in Somerset rather than Wells-on-Sea in Norfolk.

From 1807 here is another mileage mark, "WELLS-S / 129", with an increased measure of mileage to London.

Wells had a Penny Post with perhaps 10 receiving houses.  Here is an example from Axbridge "No.5" from 1824, one of the more common handstamps to find.

From 1829 here is a "WELLS SOMERSET" circular handstamp.