I have received an email from someone in Norfolk asking for someone to have a look at some old chalk workings he is considering purchasing in Norfolk. I know no more than this, but am happy to put him in touch with anyone who might be interested.

Depends what this person means by "someone having a look" - are they after proper advice on the stability? If so, that needs to be done by someone suitably qualified/insured who will want paying  for their services, the person who does the inspections on mines used by instructed groups in the Peak (Les Riley) would be my suggestion.