So, uh oh...unfortunately, I am pretty certain it is the "golden droplets" (balsam separation), though mine aren't like droplets, but more like a kind of gold-wrinkle/foil looking effect on about 1/4-1/3 of the peripheral edge of the viewfinder when looked at from the front. It kind of matches some images on line.
Lovely to see this fantastic pre-war camera being reanimated with life.
I've been using a Contax II for 15 years - it's required one proper service (undertaking the rest on my own) during this time, whereas a Kiev IVa, hasn't required any. If you are in London, the Photographica Fair is on this weekend at Vincent's Square, and many of the stallholders who specialise in repairs can advise (for free) what you might need.
One way to test if it is your rangefinder unit, might be to tape yellow cellophane over the rangefinder window on the far right of the camera and observe if there is any difference in sharpening the double image rangefinder focussing.
I experienced a chemical immersive clean for a different camera viewfinder by a UK repairer which stunned me. For the first time, I could see clearly through the viewfinder and in 20 years had never noticed just how fogged the viewfinder was. Perhaps not all CLA's are done to the same standards, so it might be worth checking which technique for cleaning the viewfinder, resilvering the beam-splitter and so on, the technician might undertake after an appraisal of the repair requirements.
The Kiev, like the Jupiter lenses, are great back-ups when you find the right one; the right year. The frame spacing challenges on the Kiev IVa are very frustrating, losing approximately one frame per 36 exp roll, which might not seem a lot, however if it is a discontinued film, every frame counts.
Perhaps now, the Contax II is seen as more quirky and requires understanding (the Contax rangefinder book is a good place to start). With the Contax II, it's a pleasure obtaining on average 39 exposures per cassette, by loading completely in the dark. This is impossible to undertake on a Leica III series rangefinder due to its upside down loading.
Hope you get it working soon!
Kind regards,
RJ