Max- i saw your add for the Zeiss 50/2 and left instructions for how I set the shim to use the Zeiss on my Nikons.
Russian lenses in Kiev mount often require filing to even fit on a Kiev. For use on a Nikon, the shim must be changed. Usually thickening it by 0.5mm works. The J-12 can be used, but expect to file down the chrome trim around the bayonet. After that, adjusting the shim makes the focus better. The Helios-103 is cheap, and a Planar formula lens. 1981 and 1982 are the best in terms of mechanical quality. But- filing might be required, the tolerances were loose. There are two set screws holding the optics in, undo them and unscrew the optics module 1/2 turn for best focus on a Nikon RF.
The J-9 85mm f2 and J-11 135 f4 cannot be used, the focus wll be too far off on the Nikon.
The Russian lenses are a mixed bag. I use a 1955 KMZ Jupiter-3 on my Contax II. They are made to that spec. Prices of S-Mount lenses are down. I picked up an S-Mount 5cm F2 for $100 not long ago. The Nikkor 5cm F1.4 in S-Mount is not much more. They will work across the entire focal range.