I´m not quite sure wether I understood your problem. ;-)
As you wrote, there isn´t much in a Kiev/Contax-Rangefinder that can get knocked out.... usually the glass block will break upon impact and thats it... but it can happen.
To check infinity alignment you need to peak on a _very_ distant object - when adjusting my FEDs and Zorkiis I tried it with a tower in 800m distance... too close, it left a bit to desire.
Karen Nakamura has given a discription how to align the rangefinder by yourself.
I heavily vote against using a groundglass for checking alignment on 35mm cameras - the tolerances are too tight, the quality of the groundglass has too much influence as does your loupe and your eye sight have.
Better to use a DIY collimator approach.
Thomas Boeder has made a visual discription, I use a slightly different method.
Mine as follows:
place a long hair in place of the film plane, mount the camera with lens (set on infinity) on a tripod, with the open back facing towards the sky. Open the shutter set at B.
Take a SLR with a lens longer that 50mm and set it to infinity. Look through the Kiev lens with the SLR - if the hair is straight, undisturbed by the microprims on the SLRs groundglass the flange to film plane distance is OK. If not you need to adjust the distance with shims under the helicoids.
I have successfully used that method with a few cameras, it´s my standard test on 6x9-folder cameras with front lens focussing that rarely are properly adjusted.
Good luck with the camera!