Old cameras have always unique character to their owns. Dont try to disturb them too much for perfection. Use your Practika as it is. Some Soviet cameras and lenses are excellent especially if they are German. I like their results if the environment is not geting direct light. Pictures turn to a burnt tone and it is excellent. I did not see a better bokeh than these cameras and you dont need to force it to give you bokeh. Daylight colors excellent , foliage is exciting and try to snap some picture of your own from a mirror at mid day and you would impress with the results. Some small mechanical error is not important , dont break the camera.