Thanks, Joe.
I will be ordering that plate and I also found the tension spring to replace the one the one that is out of shape. I just need to figure out if I have all the parts. I only have one disk and according to the pictures of a Singer 15 it looks like I may need the beehive shaped spring. The motor runs beautifully but there is no way to regulate it as I think I need to plug the motor and light into a box or something then into a foot pedal. It may take a while but I'll keep working on it.