Your guess is correct. It was sold by Rockwell, later by Delta and
instructions for use can be downloaded at the excellent owwm.com.
I have one and it works well.

"Henry Kolesnik" wrote in message
...

Does anyone know what this tool is called and what's it for? It's the
first two pics on my Photobucket site, just click on the link below.
Castings have DA$ 103, DAG 147CF & DAG 148. I'm guessing that it might be
a jig for drill bit sharpening.
Thank
Hank wd5jfr
http://s97.photobucket.com/albums/l237/wd5jfr/