I did a bunch of writeups on early DuMont sets for Radiomuseum.org. Here's the story on the RA-113 and its relatives:
http://www.radiomuseum.org/r/dumont_...ra_113_b7.html
You can find information for RA-101, 102, 103, 104, 105, 108, 109, 110, 111, 112, 113, and 119 there if you explore a little. Pictures and schematics for quite a few of the sets. Schematics also at the ETF site.
If you see any errors in the information, let me know.