[dmsfrr]

The axle may have been narrowed for wider wheels to fit under the fenders or because it was from a wider/larger car (I'm not familiar with different axle types).

In photo #4 that looks like a low-pressure compression fitting, the same type used to hook up the water line to the ice maker in your kitchen fridge, not for brake lines.
The image is a bit fuzzy, hope I'm wrong.
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