My two cents: MEAD 617 Belt Sander: https://www.google.com/search?q=vintage+mead+617+belt+sander+images&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwi7sJfrmN_VAhUJjFQKHSI_BdMQsAQIJQ&biw=1920&bih=970&safe=active&ssui=on#imgrc=zVJgS7eXTXNW_M:
STAN
Trying to help: http://www.ereplacementparts.com/jet-jdp20mf-354170-drill-press-parts-c-32652_32653_32656.html?gclid=CPro84yLjtMCFU-ewAodY7oKCw
Additionally: http://content.jettools.com/assets/manuals/354170_man_EN.pdf
Stan
Maybe--according to the description:
https://www.google.com/search?q=walker+797+transmission+jack+images&espv=2&biw=2048&bih=981&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjD5aCSwN3QAhVEhrwKHRhbD4QQsAQIGg&dpr=5#imgrc=01uyDC2LES1c8M%3A
Stan
Laser3kw [post#5] is more than likely correct IMHO. Here's what I can contribute to the mystery without photos of the entire piece.
First, this:
http://www.garagejournal.com/forum/attachment.php?attachmentid=602219&d=1480576417
Then, this:
http://kae.vampola.com/kirkwood/thomas.htm
Finally...
Well, here they are:
https://www.google.com/search?q=backup+wrench&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj-rafYsYPQAhUPwmMKHYIhBYUQsAQIKA&biw=1536&bih=736
Stan