I don't know your machine and didn't go to the links but in many (especially vintage) machines there are differences on whether the needle is raised up or down, and even whether or not the foot is up or down that make it easier/possible to change settings. Often there is a bar which can be designed as a seam in the case to show where the straight up line is, sometimes there is an additional marker of some sort on the wheel. You can turn some the dials all you want on my vintage Remington but it won't change unless the foot is down, there's a little jog in the metal bar that allows the changes to be made.
Many of my friends are surprised when I point out the little clues on machines they've been sewing on for years!