IIRC from back when I was an apprentice at BAC Hurn in the early 70s, one Speed Six was owned & flown by the man who ran the onsite newspaper shop. It had a plexiglass front section to the cockpit glazing that looked like a medieval knight's visor. Beleive it was featured in an issue of BAC's in-house paper, "Airframe" so a search may come up with some pix.