Apparently this is a coalhole Coal holes: These are covers from the period when the houses were heated with coal, into which the coal bags were poured, so that the coals did not have to enter the houses. These lids were used in the 19th and early 20th centuries.
The lid is very similar to that of another coalhole but slightly different in writing
An identical, undamaged cover, photographed in 2026 at 40 Henrietta St, London WC2E 8RF, UK: Click for a larger image