Hi i believe the shafts are under the Asda on the opposite side of the road
City's stadium is sat on what was once Richard Johnson Clapham and Morris , which was a massive iron / steel works and a company well known in the miners lamp collecting world , i think it later became part of British steel making steel cable
When Moston pit closed in 1950 their miners transfered to Bradford and worked their own coal faces from there
I was in an antique shop a couple of month ago and the guy said he had two miners lamps from Bradford pit , when i looked at them their serial numbers started with M so i left them , it was only later i thought that the lamps would have transfered across with the miners lol
The Huge gas ometer at Bradford gas works did indeed list by i believe 2% which cost the NCB a massive £1 million which back thenwould have been a huge amount of money
As a result all mining under the city center was stopped , in later years i believe Agecroft exploited the remaining deep coal from under the center of Manchester
Coal mines really are a fascinating subject
Good luck with your research
Andy