This is a Japan Victor Corporation's product.It looks something different from other radios made around the same years in Japan. General Electrics USA once had had a similar designed radio in the products lineup (I have once restored it) . So the exterior design of this radio must be a copy of it. It might represent Japanese people's yearning for USA.
Step 1: A Lump of Tar Arrived
But such condition might be acceptable because it costs only 1000JPY (US$10). And from my experience, the thicker the tar on surface, the better conditions are maintained because the tar would perform as a protector from light and oxygen, I think.
Step 2: Wash It, Wash It and Wash It Down.
Step 3: The Circuit
This something queer circuit is called "Super Triode Connection (Version 1)" invented in 1986 by Kamijo.
For details, please visit the following website:
Originally, this radio is a transformerless 5 tube superhet. I have been avoiding to build transformerless devices for averting risk of electric shock, because I am a bit of a scatterbrain. So this time I add power transformer too.
Step 4: Select the Speaker
The new speaker is SICA Z002320, coaxial 2way. It is very sensitive for a modernistic speaker.
Step 5: Modify Chassis
With an iron saw and hammer process it.