We've gotten the issue figured out. It was the clutch washer. The theory is someone prior to us buying the machine has it apart and put it back together with the washer in the wrong orientation. The machine is working like it should now. It pays to be married to a mechanical engineer. Now we just need to give it a good cleaning and oiling and a new belt and she should be good to go. Might have to adjust the treadle itself, but need the belt for that. Thank you to all the replies with your suggestions. I'm very happy to have found this forum. Everyone has such great suggestions.
Shari