Dulverton Barred Numeral cancel, 1848

The Dulverton "803" horizontal oval cancel from 1848 illustrated below does not appear to match either of the two cancels recorded in Parmenter & Smith, having four bars below rather than three (to my mind this cancel looks more like an 1844-type cancel than the one illustrated in the reference book).

It also has a "BAMPTON-D" double-arc cancel which the British County Catalogue only has in use until 1846 while Hake in Postal Markings of Devon has it in use until 1847, so this extends the known usage of this handstamp.  The cover illustrates that Dulverton was under Bampton rather than Tiverton during this period.