Which Montblanc model could a pen with silver clip, ring and nib without model number be, whose star at the end piece is set lower?

Based on the features described, an unambiguous identification is difficult. In question come, e.g., a Montblanc 320, but the clip rather suggests a model 420; then, however, the nib does not fit. Possible is a mixed construction from parts of a 320 and a 420 cap. The individual components in any case stem from the 1970s.