John Tuttle inquired about a curious part made by Bob Streicher.
John, it looks to me to be the "business end" of what is frequently
called an Automatic Center Punch or "kangaroo punch".

The L. S. Starrett company produced several different sizes.  The Model
18C can be found at this link:

http://www.starrett.com/metrology/product-detail/18C 

The reduced diameter section is sized for a heavy constant compression
spring which aids the operation.  See also drawing

http://www.starrett.com/dms/download.aspx?b=starrett3d&p=18C&i=3 

Starrett's website ( http://www.starrett.com/ ) supposedly has videos
which show the punch in operation but I was unable to get any of them
to play properly.  If the piece is hardened (test it with a file)
that's almost certainly what it is.  Even if not hardened, it may be
one he did not finish.

Someone (I don't think it was Starrett) marketed their smallest model
(18AA) which had a music roll hole-size hollow tip instead of a conical
point, together with a greatly weakened spring which was handy for
editing music rolls.  Only one hand was needed to make the hole.

John Grant