I'm looking for information on the manufacturer of a coat I recently
bought. The coat was made in August, 1941, by a company in Northampton
(England) called Wareings. I'm told the coat is a British military jacket. Does the
company still exist, and if so, how do I find information on how to
care for the jacket (full-length, wool interior and a hard, flameproof
exterior), as well as on the history of the coat and the manufacturer?

Online directory enquiries at ukphonebook.com lists no business by the
name of Wareings (or Warings) in Northampton. There is however a
Wareings Lane in Denton, 5 miles away - perhaps the factory location?
Uniform items would probably have been produced by a number of
contractors working to a specification and especially in wartime they
were probably not normal 'military' contractors.

One of Britain's foremost military museums is the Imperial War Museum
http://www.iwm.org.uk/index.htm

It would probably help others if you were able to give a more detailed
description of the coat, starting with its colour and, if you can,
which Service (ie Army, Royal Navy, Royal Air Force, or one of the
wartime auxiliary services). Perhaps you could put a photo on a
website and link to it?

Best wishes

Owain