It is a nice little camera, I own a few of them and love them all. What would you like to know?
There were basically 7 different models:
- Franka Solida JR, this was a pretty simple dual format camera, usually with a Frankar lens like yours but f/6.3
- Franka Solida Record, for this there were different variations, one of them has two big square windows in the top cover, that's one for each format, 4x4 and 6x6. Simple, like the Solida Junior, lenses usually are f/8
- Franka Solida I, like yours, is still dual format, and there is a tab at the front (can be seen on your photo) for a sliding mask in the viewfinder. It is not what I'd call "sturdy", but still, is pretty simple but not as simple as the Junior or the Record. Your f/4.5 lens was top of the range for this model. This model finally included a "real" shutter, usually a 3-speed Vario.
- Franka Solida II / III - Franka seemed to interchange the names somehow randomly, and sometimes the same camera is labeled "Solida II", "Solida III" or even plain "Solida". They were sold with a variation of lenses and shutters, although they are most commonly seen with a Radionar triplet and Prontor-S shutter. Most commonly, the II is horizontal (door opening from top to bottom) and the III is vertical (opening sideways).
- Franka Solida IIL / IIIL - This was the only model with lightmeter. BTW, the ligthmeter is Gossen. They are usually fitted with a Frankar lens like the one on your Solida I, but sometimes you can find it with a gorgeous Xenar lens. Should I mention that I am a bit biased towards Schneider-Kreuznach lenses? ;-)
- Franka Solida IIE / IIIE - The (uncoupled) rangefinder version. One can find the (most commonly seen as) Solida II (vertical opening door) or Solida III (sideways opening door) with uncoupled rangefinder, usually with Radionar on Synchro-Compur.
There were minor variations made during the production run.
Franka made cameras for others, what today we'd call "OEM", like other manufacturers did. Franka was one of the most successful in that, together with probably Balda. I have a Rolfix (6x9 model) with the original box from Montgomery Ward, and they were sold by Sears or Macy's too.