It looks like one of the enamel signs that were on railway stations. I don't know who put them there around 100 years ago, but some survive today and here's one at Oakworth station, on the Worth Valley preserved line.
With a quick measure on google maps 124 miles would indicate Peterborough as a possible location for the sign, if not railway then where would it be positioned. Can't imagine it on a roadside.
Signs similar to the one in question used to be on walls and fences at well known stop-overs like pubs and hotels.