Agree that the Carlisle one is similar, both at 20x20mm, however the shape of the '1', the angle of the fraction bar and the 'flat' base to the '2' appear to me as Fig 135. This is L187(1) in BCC Vol. 3, 2nd edition, page 32. However, H and S do say in their Chapter III to be aware of over-inking an...

Re the lovely Bristol to Edinburgh cover, I believe the boxed half was added in London (H and S Fig 135) which would make the mileage total 518 (122 to London and then 396 to Edinburgh). Between 1801 and September 1838 the charge was for the actual distance travelled ie the single rate would have be...