I see no one knows anything about your machine. I did a search for it, but could find no matches.
You can pretty much assume that it was sold under brands other than Penny's. It may have been sold under many different names. Chances are it was made in Japan, depending on it's age.
I have two suggestions if no one can help. One is to look at sewing machine manuals on the sites that sell them. I think Tia's is one of the big ones. They put a drawing on the front of the manual. Look for one that matches yours. Note that you have one knob, one lever + the tension knob. The drop feed dog knob is by the bobbin winder. Those little buttons on top are are kind of unusual, so maybe looking for those would help.
Post it again in a few weeks. Someone may know that time. I id'd my sister's machine on the second post.
bkay