Help with spike

[yaro990]

Could you help me to identify this type of the spike. I've never seen this type before. Thank you in advance.

 

[yaro990]

Additional photos

 

[pickelhauben]

Never seen anything like it.
Perhaps a prototype of the removable spike that never came to use.

Or perhaps it is a proto of a weeble made back in 1914
Just kidding.

 

[Peter B]

It kind of reminds me of some of the stranger spikes on the German Tropic Helmets.

 

[b.loree]

I have seen the threaded rod soldered up into the tip a couple of times on what I felt were older spikes but never the rest of this example.