OK guys & gals, I'm going to get some kerosene and try it first, then go to Liquid Wrench or TriFlow oil.
Linda R, it is a treadle & I don't see the next post you mentioned. But, I started the other day with the face plate off as well as the round cover plate in the back & oiling & brushing with a toothbrush to no avail. I have another treadle and looked at it and where parts should be moving ( the big joint of the connecting rod inside the round back plate, the bars under the bed, bobbin area, and nothing moves.
Thanks for the encouragement! Will keep at it.