This looks a like a StitchMaster that I just worked on, similar knobs and buttons and end cover. I could find very little on the Stitchmaster machine as most searches are sent off into a new company by that name that does not make sewing machines. Here is something I found on Zenith that was interesting.
The Zenith Sewing Machine was a Product sold by MW, or Marshall Wells of Canada Limited, 1395 Ellice Avenue, Winnipeg 21, Manitoba. ( This is the Address shown on the Sewing Machine Warranty Card.) Marshall Wells was a Hardware Store Franchaise, but as far as I know, they are no longer in Business. The Zenith Automatic Zig-Zag Sewing Machine, which I am familiar with, was sold in 1952. As far as the Manufacturer, it appears it may have been made in India, and sold primarily in Asian countries.