Make your own collimator. Take a long hair and tape it straight on the film rails and over the film plane. Then take an slr with a split-image rangefinder and focus it to infinity (better use a very distant object than trusting the scale, using moderate tele-lenses is easier and more precise than wide-angles). Position both cameras facing each other lens to lens. Look through the viewfinder of the slr and adjust focus on the folder untill the hair is no longer split. Now carefully set the folders focus-ring which you have loosened beforehand to infinity and fix it in this position. I did this with an Agfa Record II some month ago and was quite surprised by its nice performance.