The company I worked for manufactured large close control specialised air conditioners for clean rooms, labs, hospitals, telephone exchanges and data centre's, in fact anywhere where the temp and humidity had to stay within very close tolerances. (Takes a lot of expertise in hot humid tropical countries).
Highly skilled workforce in Sydney. Machines were exported all over Asia. (I was the export sales manager).
Now all manufacturing gone to China.
It's the same everywhere mate, you can't just look at a derelict factory in Hyde and say "Thatcher closed that down"
The world economy closed it down....China and Asia have become the factories of the world. It's just the way things are. Thatcher didn't end the textile industry in the north of England, it was ended before her time, and the rest just followed.
And no I'm not a Thatcherite so please stop having me defend the cow. :)