Not able to help on the original query but on the wider issue of local sayings around the West Midlands / Black Country area, my mother (and others) used the following expression (in the dialect) "Yow bay osterd ay".

This was usually in response to someone who was being a bit offensive or challenging; it is directly translated as " You are not as high as a horse turd"- or more loosely "You are a little person who is not worth listening to".