When you look at it again, look for how it is powered. Some of the old electric portables came with a knee bar that is stored inside the domed top. These types have a hole in the lower right area of the base where you insert the bar. When there is a knee bar, there is no foot pedal. I have one like this.
If the machine is a knee bar type but doesn't have the knee bar, it isn't worth as much. Knee bars can be hard to find, but Billy (Lostn51) often has one.
If it's not a top-loading machine, check that the bobbin case is in the machine. Replacing a bobbin case costs extra money too.