I recently acquired an Olympia SM7 that seemed to be working fine, until it got to the end of the page, and the carriage would no longer move. I found out that the main spring must have come loose within the drum. I removed the draw band from it's attachment on the carriage and when I tried to rewind the the drum, it just keeps clicking and loosing tension after one spin. I've looked into opening up the drum, but this sounds like a total pain. So wondering if anyone has extra drum lying around that you wouldn't mind selling