Dawn,
I don't know that it's a class 15 clone. I'm pretty sure those are restricted to the machines that copy the shape of the Singer Mdl 15s. But, it is obviously a Japanese made machine and a very nice one at that.
It originally came in a cabinet. You can tell that by the curved piece on the foot controller. That curved piece makes it a knee controller. The controller would have been mounted in a bracket up under the bottom of the cabinet.
I'll be once you find it a home it will sew very nice.
Joe