Repair of Minolta XE7 film advance

My Minolta XE7 which I purchased in Japan around 1978-79, has been broke for a long time and have been told in the past that there were no parts around to repair.

The film advance lever when advanced will tighten and will not complete a full advance. The lever is then free to move but will not return to start position, and then unable to take picture to attempt to advance film again.