I'm doing a bit of research into shops that were around in the '80s. Where would I go to find out who the parent companies or owners were? Companies House or would the local libraries have the information?
The City Business Library in London might be able to help. The public library in Birmingham used to have a big business information Library , but there have been so many cutbacks, ( and the BPL is rebuilding and moving), so I can only hope it still exists.
Biggest Library I know on that subject is the Saeed Business School in Oxford, but you might not be able to arrange access there.