The OP's blurb says 'Germany'; one of the earliest German 120 boxes would be a Goerz-branded Box Tengor. The exact spec of the B-T varies, but some have three aperture stops and three-zone focus.
My oldest box is an Ensign 'Duo-Ensign 2¼B' from about 1930. That has a meniscus achromat (a meniscus, but it's two elements glued together) three aperture stops, and a portrait-range supplementary lens on a slider. There was a model with a Rapid Rectilinear lens at extra cost; those models have RR in the name, but you don't see many of them. One feature of my camera is that it has Watson viewfinders; tiny ground-glass screens, instead of tiny condenser lenses ('Brilliant finders') familiar on a more modern box camera. They are a little harder to use in dim light.
You could search through some of these at Camera-wiki: your choice is obviously affected by what you can find to buy that's in good condition.
camera-wiki.org
A lot of those will be 620. Among the Kodak, I think a camera with 'No.2' in its name is probably for 120. There's a subcategory there for German (and one for Japanese; someone created a category for two cameras).
Was it the OP who wanted square format? There is a category for 6x6.
camera-wiki.org