Longworth Scientific Instrument Co
of Longworth Road, Oxford. Telephone: Oxford 3866. Cables: "Instrument, Oxford". Works: Abingdon, Berks, (now Oxon)
1943 Company founded by personnel from the Department of Anaesthetics at Oxford University.
One of its first products was the Macintosh Laryngoscope, then a revolutionary design invented by the late Sir Robert Macintosh, Professor of Anaesthetics.
1947 Listed Exhibitor - British Industries Fair. Manufacturers of Medical and Scientific Instruments, including Hospital and Laboratory Equipment, Anaesthetic and Electromedical Apparatus, Laryngoscopes, etc. (Olympia, Ground Floor, Stand No. E.1782) 
Expansion into export markets prompted a move to larger premises at Abingdon, and eventually the company name was changed to Penlon Ltd.
1988 November. History of Longworth Scientific Instrument Co Ltd. By Sir Anthony Jephcott. Hardcover - published by Regency Press. 
1996 In October, Penlon regained its status as an independent company.
Sources of Information
-  Penlon website