Super rare antique retro brass ballpoint pen, late Taisho to early Showa era

Thank you for viewing!
Ultra-rare antique brass ballpoint pen, max9.
[For those captivated by vintage stationery]

This is a rare brass ballpoint pen.

I purchased it, believing it to be from the late Taisho or early Showa era.
It's a short ballpoint pen, but it has a substantial weight.

The inscription "max9" is engraved near the bottom of the cap.

Isn't this a rather rare brass ballpoint pen?

Currently, a refill is inserted, but the ink doesn't flow.
Please replace it with your preferred refill after purchase!

Please carefully examine the condition in the photos.

As it's been stored by a private individual, please refrain from purchasing if you are overly concerned about condition.