Checking eBay, it says the item is sold. Do you have it?
It's obviously a homebrew set, built in the oldest tube style, very early twenties. The builder must have built in two steps: the radio first, then later on built an amplifier so made a new cabinet to contain them both. The use of external terminals on both the receiver and amplifier and connecting them together with brass strap jumpers is an early twenties way of doing things. This was done so a person could have a headset radio first and save up to get the amplifer for a horn. By a year or two later audio amplifiers would be built into sets without the external jumpers. I see an ST type tube in the amp so someone was using this at least into the thirties or tried later to rehab it.
There is no Riders on this, it's a homebrew! Most wiring in those days was bare bus bar, often square in cross section. The circuits are very simple, however, with few components other than the essentials, so should be easy to trace out and draw a schematic. The audio amplifier has two tubes with a filament rheostat for each. There are three phone jacks which probably work like this: The first one on the left is for the output of the radio with no further amplification. The middle one uses one amp tube. The one on the right uses both amp tubes. Often these jacks are arranged with switch points that turn on or off the appropriate filaments. The amplifier is going to be similar to the "senior amplifier" by RCA on the attached: once this opens click on the "eyeball" to go to the schematic.
http://www.nostalgiaair.org/Resources/349/M0040349.htm