This Imperial is actually a renamed Case model 601 which was manufactured by the Case Electric Corporation of Marion Indiana.  The Case 601 had three bands and used a mixture of large pin and octal glass tubes.  The later version of the 601, the 610, had four bands and used all octal metal tubes.  This radio was also sold under the brand names of Silvertone (Sears) and Radio Vogue.  The most interesting feature of this radio is the "Jumbo" dial. It is a large multi colored, side lit glass dial that seems to be oversized for such a medium sized cabinet.
    Case Electric Corp. was originally known as the Indiana Manufacturing & Electric Corp., known for the "Indiana Hyperdyne" and "Case" brand of radios manufactured from 1923 to 1928.  It was in 1928 that the Indiana Manufacturing & Electric Mfg. Corp. changed their name to Case. From 1929 to 1934 Case did not make any radios, almost as if the company went dormant.  Then in 1935 production started up for the Case line of radios for the 1936 season.  Unfortunately Case failed to submit yearly corporation reports, which is required, to the state of Indiana during the years of 1929 to 1934.  Soon after Case went back into production, the state of Indiana held hearings on the future status of the company and on April 2, 1936 the state of Indiana officially dissolved the company. 
    I bought this radio from a prominent antique radio collector/dealer, from Minnesota, in 1990.

Tube Line Up:
6D6.....R.F. Amplifier
6A7G.....1st. Detector/Mixer
6K7G......I.F. Amplifier
75.....2nd. Detector
6F6.....Audio Output
80.....Rectifier

Dimensions:
Height...19 inches
Width...15.75 inches
Depth...10.25 inches

Frequency Ranges:
BC Band (Red)...550 kHz to 1700 kHz
Police Band (Green)...1.9 MHz to 6.0 MHz
SW Band (Yellow)...6.0 MHz to 18.0 MHz
I.F.Freq....262.5 kHz

Power Source:
AC.....110 Volts

Schematic and information (Case model 601)