It is slightly smaller than the Hub lamps that I have had in the past.Might be the very rare pedal lamp , with that mounting bracket
Let's see your hublamp.I'm considering selling this. I already have one on my 54" Columbia, though it is not as nice as this one. But it's been on there for decades. Thanks for identifying this, BicyclerNY!
Pictures are posted aboveLet's see your hublamp.