I've had this for a few years, bought off our local Kiwi auction site. I bought it as much out of curiosity as anything else, never having come across one before. Camerapedia suggests that this is a Weha Chrome-Six (III) dating from around 1941.
When I got it the RF patch was very faint and shutter was a bit erratic, so had the shutter CLA'd by someone that knows what he's doing

Recalling the shutter-man's comment that the shutter seemed somewhat crude in construction, and seeing that the few that I had seen elsewhere (Ebay) were often non-functioning, I thought I'd have a go at sorting the RF patch. I have sorted the RF mirrors on a couple of other cameras - the uncoupled RF on the Agifold, and the coupled RF on the wonderful Certo 6. The difference being that with those, I was able to find some online resources to guide me. With the Weha Chrome-Six, there's very little material at all out there, and what little I have found is in Japanese.
So, first step was to figure out how to get the top off. There are strap lugs on both sides of the top plate, each held with two screws. The only other screw I could see was a single screw in the cold-shoe. So, I removed the four strap-lug screws and gently tried moving the top plate with my fingers. It seemed to come up a bit, and a little more gentle persuasion and the top came up a bit more, until blocked by the shutter button. This simply unscrews, then the top plate is free. Simples!
Getting the top plate off revealed the insides, showing a fairly "artisanal" looking viewfinder and RF. The material appears to be some type of bakelite type material, and the machining is quite basic. Certainly nothing like the construction of the other two cameras mentioned above.
The limited literature on these cameras indicates some confusion over the actual film counter mechanism. A film counter dial suggests a modern somewhat automated mechanism, however it too is rather basic. The counter is not in any way automated, with no auto-frame counter/stop, and no double exposure prevention. The counter works by way of a red window on the 6x9 track to set the initial frame, similar to the Super Ikonta B. From that point you move the little knob to "O" and line the frame counter dial to "1", then twist the little knob to "S". There is a toothed wheel in the film supply chamber that rides along the film backing paper, a shaft from this drives the indicator arrow wheel which you then line up with the counter. While somewhat basic, it does work well, though an auto-stop or even just a double exposure prevention would have been nice. Still, at least it keeps it simple enough for someone like me to work on!
The RF mechanism consists of the Super Ikonta B style prism (but here uses a slightly different optical method) coupled with RF windows that are separate from the (very basic) viewfinder. The "half-silvered" mirror is held in a small metal holder that is screwed to the bakelite upper frame. There are three screws on the right side (small top and bottom grub screws, a larger screw in the middle), one difficult-to-access screw on the left. The two grub screws are to adjust the vertical alignment. A combination of adjusting these and the larger locating screw on the right appears to control the horizontal alignment. I removed the mirror housing to find a "munted" (kiwi slang!) half-silvered mirror. Fortunately I have a couple of pieces of replacement mirror that I got some time ago off Edmunds. A quick measure, mark, glass cutter and snap and I have a replacement. I played around a bit to better understand the adjustments before using a couple of spots of clear modelling paint to secure the mirror in its little housing. I then spent a half hour or so of trial and error getting first the horizontal alignment at infinity, then adjusting the little grub screws to sort the vertical alignment.
I cleaned the inside of the top housing and refreshed the poorly applied matt black paint around the viewfinder/RF areas. Then I put back the top plate and the first screw, before the second little screw made a bid for freedom by jumping off the desk and onto the carpet.... 10 minutes or so later, I found the escapee and returned it to its proper captive place!
A quick check with it all back together confirmed the lens and RF agreed on where infinity was and they both agreed on the minimum focus point too. Vertical alignment seemed to be spot on as well. Shutter seems to fire at all speeds, though how accurately I don't really know. The aperture blades seem to adjust freely too. Result!
Next step is to see if it works as a proper camera. I do recall the lens seemed only to be sharp in the centre, on par with a budget triplet. Potentially there's a lens element in the wrong way round, but that'll be something for another day.