The 1937 Poor's Manual of Industrials listed the following about Majestic and Case. 

Majestic Radio & Television Corp. was incorporated Sept. 23, 1936 in Delaware and acquired a business commenced by Davega Stores Corp. originally for its soe account in May, 1936, with the purchase of all the rights, title and interest formerly of Grigsby-Grunow Co. in and to the trademarks "Majestic" and "Mighty Monarch of the Air." Corporation is now producing 11 models of Majestic radios and is developing four additional models and an advanced type of automobile radio. Radio sets are made under contract in the Case Electric Corp. plant in Marion, Indiana with an estimated plant capacity of 300,000 radios per annum.

The Majestic Radio Company had an option with Case Electric to purchase the assets of case. 

Option: Under its contract with Case Electric Corp., Majestic Corporation is entitled to purchase 10,000 shares of Case Electric Corp. at any time on or prior to Sept. 1, 1937 at $13.50 a share, plus any increase in value of said shares as may arise from earnings transferred to surplus between July 1, 1936 and date of exercise of said option,with an election to the holders of the 8,901 Case shares now outstanding to have their shares delivered upon the exercise of such option, instead of shares authorized but unissued. 

The 1938 Poor's Manual of Industrials explained the end of Case Electric. 

During 1937 the Majestic Corp. purchased from Case Electric Corp. manufacturing licenses, machinery and equipment and transferred operations formerly conducted by Case Electric Corp. in Marion, Indiana to Chicago, Illinois.

Majestic is a name of multiple use. There is terrible confusion in literature about three separate companies.
To avoid doublets and achieve unambiguous allocation of radio models the relations of Majestic vs. Grigsby-Grunow and Grunow/General Household Utilities are listed in the following.

1) Company Grigsby-Grunow went bankrupt in 1932 and its models ended with the 1933 season. Models were often named Majestic.
It was followed by two successing companies:

2) Company Majestic Radio & Television started in 1933

3) Company General Household Utilities started also in 1933,
featuring the model name Grunow.

Please be extremely careful to distinguish the 3 different manufacturers, in particular for 1933 models.

Rider's is listing in the index "Grigsby-Grunow" models, but to find are they under "Majestic" in the files (although the sheets themselves are headed Grigsby-Grunow...).
Similar confusion is found in Bunis/Slusser, while Machine Age to jet Age puts together No.1 and 2, separating No.3.
Beitman calls both No.1 and 2 Majestic, but separating "old" and  "new".
Grinder does separate, but lists models from the late 1930's also under Grigsby-Grunow (No.1).