You have a jem there. She is indeed a Singer 185. I don't think she is a 185J because they came in a different case than yours is, and I agree, I think the J's were made in Canada. They had the brown case.
I was fortunate enough to have my mother gift me her old sewing machine. None other that the 185J. I was so afraid I would break something as it had not been used in years and years. I took it home and oiled every moving part with lots of oil, then I let it sit with a towel under it. Next day I would wipe off the oil and reoil. Did that for a week and then put my foot on the pedal. She ran like a dream. I learned to sew on that little baby, and I do almost all my quilt piecing on it since mom was kind enough to give her to me. That little green machine is a work horse. There is not one iota of plastic in her, so she is heavy, but she will sew canvas, or chiffon, whatever you want her to.
You are one lucky lady to have her.
amh