Looking for headlight connector for 1924 model 45

[Rocketron]

Hi, I'm missing the threaded cap on the end of the corrugated tube that carries the wire to one of my headlights.  I do have the corresponding socket but it's broken so I could use that too.  Here is a photo of the other side that is still intact.  I feel like this will be a difficult part to find since it's so small.  Anyone have a spare or alternatively a suggestion of a modern day replacement?