This radio was built in 1938 as a battery set. The schematic below shows a B battery eliminator and connections for the A battery, allowing it to run on 6 Volts. http://www.nostalgiaair.org/Resources/304/M0018304.htm
This set was owned by my sister-in-law's mother who lived on a remote farm. Sometime later electricity must have arrived as a mod has been made with a new transformer and an 80 rectifier tube added as an outboard. See photo below. Although the workamanship is terrible, sister-in-law remebers listening to it as she grew up in the 50's. Unfortunately, due to the rat's nest wiring, space ties and lack of modification documentation I will not be able to restore this set. Was it possible that modification instructions were published by other than the manufacturer to allow owners to upgrade their battery sets?
The wires that appear to be cut in the photo were actually chewed by varmints during storage. They even chewed a piece out of the antenna coil. Ate the grid cap also!