The Model 30 and 31 are two-manual organs with a 25-note pedal clavier. Each manual has 61 notes. According to Robert Eby in Electronic Organs (1953):

The Model 30 and 31 organs vary in only one respect: The tone chamber for the Model 30 is contained in the organ console, while the Model 31 utilizes a separate tone cabinet. The console dimensions and stops of both instruments are identical as are the pedals, bench, and other appointments.

The appearance of the Models 30 and 31 is a console organ with spindle legs. The 31 was designed to work with the Wurlitzer 310 tone cabinet.

Eby also writes: “A patented re-entry system provides a faster action, yet smooth attack.” It is unclear what patent this may refer to—possibly 2,570,178. This was a patent filed in 1947 by inventor Victor I. Zuck, a former Everett employee now working for Wurlitzer.

Patent 2,570,178 describes a modification to the pallets, or the valves that send air to the reeds when an organ key is depressed. Summarizing the prior art, the patent notes that existing techniques for engaging organ reeds require “cumbersome, complex and costly apparatus which is not well adapted to many uses such, for example, as in a compact and inexpensive organ intended for home use.” In contrast, the patent describes a modified pallet system that was intended to reduce the size and complexity of the tone generators while improving playability and maintaining tonal quality. It explains:

A further object of the invention is to provide a simplified operating mechanism for the pallets of an organ to reduce the cost thereof, to minimize the amount of maintenance required, and to provide a delicate key touch and quick response through a reduction in the inertia of, and frictional losses in, the pallet mechanism.

Regardless of whether this is the patent described by Eby, it does indicate that Wurlitzer was continuing to develop the keyed reed organ technology that it acquired from Everett.