L'Iloca IIa est une évolution du Iloca II. Il en diffère par :

une meilleure intégration du compteur dans le capot.
Déclencheur sur le capot, et non plus sur le fût de l'objectif.
Meilleure préhension des commandes grâce à un nouveau dessin de celles-ci sur l'objectif et l'obturateur

Sur le IIa, l'obturateur peut être un Prontor-S ou un Prontor-SV. Il y a eu deux versions successives du IIa se distinguant par des détails esthétiques.

Jusqu'à présent, je n'ai jamais vu de IIa ayant le bouton de mise au point comme celui de la gravure. Généralement le bouton est plus large, et bilobé.

The company Iloca Kamera-Werk has its origins in another company established in Hamburg under the name Ilca in the late 1940s, but it was quickly taken over around 1949 by Wilhelm Witt, who led it to a certain level of success that unfortunately didn't last.
It only produced cameras under the name Iloca from the early 1950s until 1959 (bankruptcy in the spring of 1960). It is best known for its stereo cameras. The majority of its production was aimed at exports, especially to the United States. For exports to the USA, Iloca products were sometimes rebranded with different names (such as the  Realist ST-45). Alternatively, the company partnered with importers/manufacturers like Tower (Sears, Roebuck and Co.), Photrix (Montgomery Ward), Argus (Argus Inc.), and even Graflex (Graflex Inc.).
It's interesting to note that the company's bankruptcy was the result of a battle among giants in the emerging German industry, which took the form of a refusal to supply new automatic shutters that Iloca was seeking from Friedrich Deckel in Munich. Iloca may have fallen victim to a clash between the Zeiss Ikon group and the one that owned Voigtländer over the acquisition of these new automatic shutters. Iloca, it is said, was ready with next-generation products, but none of the major groups seemed to favor this, possibly pressuring Friedrich Deckel not to deliver 3,000 advanced shutters, which forced W. Witt's company to go out of business.
(source: Die Zeit, April 8, 1960).

Another reason for the company's bankruptcy, as developed by Wilhelm Witt, may have been the excessive focus on stereo cameras. The resurgence of stereo photography in the post-World War II era was short-lived, and it cannot be ruled out that the system developed around the View-Master may have adversely affected traditional stereo photography on 35mm film.
However, before disappearing, Iloca introduced a sophisticated camera to the market, the Iloca Electric, a large 24x36 motorized camera, the first of its kind, which sold well in the USA.