A completely broken rotary mechanism of the 146 can practically not be repaired in a reasonable cost-benefit ratio, since often the second sleeve at the front towards the cork seal is torn. Before further disassembly steps, first the year of manufacture should be determined and the defect precisely localised, e.g. based on photos or comparison pictures of known collector sites. On reassembly, the new cork must be set with the mechanism screwed in, since from behind there is no access; tightness is the decisive criterion. Overall, the repair counts as very elaborate; a 142 can be restored comparatively more easily.