Newns / Eagle Coachworks of Portsmouth Road, Thames Ditton were mentioned in Motor Sport Magazine, November 1935 as per attached image.
It looks as if Eagle, like a lot of companies in WWII, then turned its ability to helping the war effort; in this case making plexiglass domes for the RAF:
https://www.gettyimages.ie/detail/news-photo/the-work-force-of-eagle-components-ltd-newnes-factory-news-photo/591982074I realise this is
Eagle Components rather than
Eagle Coachwork(s) but given the reference to Newnes (sic), Portsmouth Road and Thames Ditton it seems reasonable to assume it's related!