My MIL's main machine was a Golden Touch&Sew (I believe that is model 624 or there abouts). She took in jobs to make extra money while DH was growing up and sewed everything on it.
Over a year ago we brought it home to fix up for her. She had taken it in to a dealer and they dipped it, and then messed up the adjustments. She took it somewhere else and they told her it wasn't fixable as dipping it had ruined some of the nylon parts. So it sat for about 15 years never being looked at, and now that DH fixes them, he had a go.
Nothing wrong inside but horribly out of adjustment. He got it all working and back together, and we took it back. MIL was very happy to get it back in working condition, unfortunately her condition worsened so rapidly that she was never able to use it.
Now it's waiting for when DH and I get back down there (probably this fall) and it will come home and have a place of honor at my house. She loved that machine, and that is why it's important to me.