We had one just like it. A 1960. Top speed about 62 MPH. Maybe a little more going down a hill and less into a head wind.
Also remember you had to open the hood to fuel it up. It wasn’t until later they added the access to the fuel tank with a little trap door.
I sure do remember opening the hood to fuel the tank. Going up steep mountain grades mine topped out at 25 mph with that 36 HP engine.