Paul,
I agree, this does look like a Emerson 600/639.
These often were supplied with a bakelite case that often will be destroyed in shipping, so an unattached chassis does not surprise me.
I have an unrestored one with bakelite cabinet, that I bought simply to get a good 7JP4, but I took pity on the little critter and have decided to restore it. A check resistance check indicated there was no short, so I brought it up with a variac in series with a 10 ohm, 25 watt resistor, while monitoring the voltage across the resistor and the set worked as-found!!! This won't be done again until I get ready to recap it. If you need anything measured, just holler!
By the way, there is a Sam's schematic for this set at
http://www.earlytelevision.org/tv_sc..._diagrams.html
James