This is a beautiful enamel sign dates back to the period when The Morning Post was in circulation, which was from 1772 to 1937. but these enamel signs started to be prevelent from the 1880s onwards. So based on this information this suggests that this sign dates between 1880 and 1937 and after lots of research it appears that this sign could possibly be a one-off.

A publisher named John Bell founded The Morning Post and this daily newspaper quickly became a staple for Londoners, offering a mix of news, opinions, and advertisements.

In 1788,  Peter and Daniel Stuart took over and its circulation soared but by 1924 the paper was purchased by Lord Rothermere, who also owned the Daily Mail and after more than 160 years of independent publishing, The Morning Post became The Daily Telegraph, marking the end of an era."