Technics SA-700 Volume control issue

Hello. My name is Ignacio, writing from Buenos Aires, Argentina. I have an SA700. My father bought it about 45 years ago, so it's been in the family forever. The system works well. It has some false contacts in the selectors, nothing serious, but I have a problem with the volume control. Over time, the false contacts in the volume control intensified to the point where I have to search and search until the tracks on both channels make contact. This happens to both the main output and the remote output. I wonder if it's possible to get the original module. Could you tell me where to ask/look? My idea is to get the module and take it to a technician to replace it. I'll be waiting. Thank you very much!