Here's a [COLOR=DarkSlateBlue]short write-up[/COLOR] I did a few months back on the earlier model 530/2.
There often were several variations within each model. The first was the Super Ikonta 530/2 with plunger style shutter release followed by the 530/2 with body release. The 531/2 introduced double-exposure prevention.
The camera returned after World War war. Zeiss Ikon also produced the uncoupled rangefinder model 524/2 -- a sibling to the Mess Ikonta 6x6 524/16. The 524/2 was 6x9 only. Both cameras are similar in their styling to the folding Contina, which was designed by the [COLOR=DarkSlateBlue]legendary Hubert Nerwin.[/COLOR]