Don't know if anyone can recognise this?

I saw an enamelled sign yesterday with the legend: BY REQUEST  (black on 
white)

The sign has two holes along the upper edge as if it was designed to be 
hooked onto something (or fastened on to a chain.)

The sign is enamelled both sides, so the holes are not intended for screws.

The sign turned up in mid-essex but neither the current owner nor 
anybody else who has seen it has any idea where it comes from - it is 
obviously not local to the area.

The owner is interested in knowing its origin - can anybody help?

I have taken a photograph of it and can post a link to it if anyone 
thinks it might help but I'm sure the description above should suffice.

Terry