Here is a variation that I have not seen documented anywhere in reference books or online. It may have been overlooked or possibly just that there was not that many done this way.
It is also that type of variation not always visible in photos. Until now....
The good news to share is the steel barrel pin is dome one end and on the worm gear (spiral end) it is crimped. On the other 1 million I have looked at
they have been dome and riveted (rounded)It was an interesting exercise in trying to photograph for the forum and get the steel pin in focus. The base plate or spiral gear was confusing the camera focus. Hope the images show the detail.
What is interesting from a model evolving point of view is that this crimped steel pin is on the second casting with the narrow braces on the axle supports. (The first casting has smooth supports)
If the crimping was being trialed it would have been more logical for it to be on the first casting unless this was a method being considered in lieu of the riveted end which tend to vary in shape. (and before the introduction of the plastic pivot pin)
The pivot pin hole under the hopper is the oval type.
A second image captures all the other key variation features.
A third image is a close up.
