I think the 'C' is just an ID of the date-stamp itself, related to the counter position / PO clerk who used it. It's nothing to do with time.

Barrie Jay's London volume of the British County Catalogue series lists them. Incidentally the '2' over the original '11'd charge is just a squiggle cancelling the number. Hope that helps.

This Liverpool to London letter was mis-rated as a single at 11d, when it reached London it was re-evaluated as a double letter - the original charge was deleted and the change authorised by the inspector's crown mark (one of several types in use 1680-1840) and the double rate of 1s 10d added.

It's an individual identity hand-stamp issued to Belgian postmen - I've come across various combinations of letters and numbers.

The net and postbag in the illustration were a separate function of the TPO to collect or drop bags of mail without the train stopping - it was termed the 'apparatus'.

The general late fee service finished before WWII. This cover is from a separate service linked to the railway TPOs/sorting carriages : a letter could be posted into the carriage through a letter-box while it was at a station, if it had an additional stamp for a late fee. Letters so posted without a...

Generally accepted as 'Posted Late' i.e. Too Late for the day's post - there's no indication of a late fee being involved. Recorded 1840-48 although I have an example from 1849.