I have a Jensen manufactured Bostwick tweeter from about 1935... the "type q" field coil horn...
I listen sometimes with a pair of 8" field coils marked "EARL made in England" that I don't really know much about... they are also mid 30's. They're very nice midrange units, although they definitely were intended as full-range, probably came from radios.
Those are my oldest that I actually put listening hours on... most of my listening is on speakers that predate about 1955.
I had the feeling I had already replied to this thread at some point, but I don't think I had the Earl speakers then...
I have another oddball from the same manufacturer, but just one. It's a very *EARL*y alnico haha... ha... seems they made very high quality drivers, don't know what happened to the company. Maybe dissolved during WWII? Would love if anyone had any info on the UK manufacturer "Earl." I'm aware of the "C.A Earl" branded radios, and I don't think they are related. Label is all-caps, almost Arial font, very plain... Hanover Park, London, they say...
Don't know how I ended up with multiple items from a manufacturer that seems to have no trace of existence... my luck seems bring me odd things... the pair came together from a radio-cave estate sale... just loose drivers off a shelf... but anytime you see a pair of something, you get interested cause.... that's weird for stuff that old. I've wondered if the original radio had both in one box... "fancy" for that time. Some of the most valuable radios of that era I've fixed are those with multiple drivers.