Here you go. Looks like 90 volts and 1.5 volts. There's a "battery thrift switch." When used on batteries, you'd switch it so the resistors were in line when the batteries were new. Then as they aged and performance dropped off, you'd switch the resistors out so the set would be connected to the battery direct.
http://www.nostalgiaair.org/PagesByM...6/M0017446.pdf
Edit: Looking quickly at the schematic I see two 10mfd @ 150V electrolytics. These are probably dried out and should be replaced. I would bet that this radio was not used much as it's post-war and the power line probably got to the farm not long after. My guess is that if the tube filaments are good, the 'lytics are replaced, and power is applied, this would work. Of course paper caps should be replaced but I'm guessing it would work from the get-go.