My nan had a very similar mower to yours that was badged as a Pace. It would have been among the earliest production runs, around 1976, with that chassis and engine top combo. Hers was, of course the top mounted cup starter and the cover was white Werth a hammered finish blue chassis. Yours has the deluxe 8" ball bearing rear wheels and ball bearing fronts. Much nicer to push around than the nylon bearing wheels that were on my late nan's.
Here's one I converted to 8" rear ball bearing wheels. The fronts are the original nylon bearing type. I had to swap the rear axle as they are slightly different to the one with the 7" rear nylon sleeve bearing originals.
The 6" fronts are a straight swap -which I haven't got around to yet.
Note the engine top developed for this series side pull motor.
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!