Quote:
As usual, "it depends"...
First of all, there are #181 cancellations (non-duplex), but instead what you have is a #181 DUPLEX cancellation. Notice the part of another ring at the bottom of the cancellation (at the left of the image). Your stamp is Scott #7 (first issued in 1858).
From around 1854 up through around 1862, Danish numeral cancellation 181 (non-duplex) was used on the railway line Sjællandsek Jb.P. When the non-duplex cancel use actually stopped needs to be double-checked.
However, what you have, the duplex version, was used on the same railway line through the 1863 stamp issue (meaning that it, the duplex version, can be found on Scott #9 & 10, while the the NON-duplex version is NOT found on Scott #9 & 10).
All uses / types of #181 were discontinued after 1863, when many numeral cancellations were reassigned (as discussed in another recent thread).
Not true, the duplex was, and continued to be, assigned to Sjællandske Jb.P, from start till whenever it exactly was taken out, which was after april 1884 when most of the numeral cancels were taking out of use.