''Yo might find werk et Brummagum'' or ''Yo doe werk et Brummagum'' Was a common cry from a Black Country 'gaffer' in response to poor, or inaccurate workmanship.....or as was the similar: ''Brummagum Gimcrack'' or ''Brummagum gew-gaw'' - meaning, bright, shiny, pretty things, that had no real use or purpose.
Another was, for any item that had a small defect, but was otherwise serviceable ''send that un to Brummagum......and/or ''they'll never notice!''
My father used the eponymous 'as much use as a ' - as in: ''as much use as a Brummagum bucket!'' I asked once what the expression meant: ''first, he said ''they don't make buckets in Birmingham; and secondly, if they did, they'd have two holes - a big un and a little un!''
Or, as in a matter of rare praise: ''It might belong o' Bilston'' meaning something that was on the way to being workmanlike.
Regarding 'Wolverhampton' with grudging respect/or understatement: ''They con mek a thing or two theer''
I offer these merely as 'historical insights' only......(sniggers wildly and runs off)