Thank you, everyone. I did some google searching and found a lot of info, including posts here. They are not uncommon, and like new sets can be purchased for between 80 and $120.
The cool factor for me is that they were my grandfather's. He came into Ellis Island from Russia as a boy in the late 1860s to early 1870s if I recall correctly. I would guess that these are from the 1890s or early 1900s.
Concerning cleaning, I am thinking about putting them in Evaporust to remove the surface rust. Since the Russel Jennings sets are relatively common, I may lightly sand and re-varnish the outside of the oak box.
The augers are pretty common, but I found that if the brace is also a Russel Jennings, that it could be very rare. It is still packed from my recent move, so I probably won't know until spring.