How to dismantle old propelling pencil?

This a reworded request that was unanswered.

I have an old propelling pencil (Onoto). You advance the lead by
turning the cone at the writing end.

I want to get the mechanism out so that I can clear the socket that
holds the lead.

My problem is that I can't see how to separate the winding mechanism
from the plastic body of the pencil. It looks as if the whole
mechanism is just pushed into the end of the plastic holder. Certainly
I can't see any connection between the clip end and the winding
mechanism at the writing end.

The pencil dates from the middle of the 20th century, I presume. Photo
at:

http://box.net/public/richwrig/dfiles/OnotoPencil.jpg