Janet - I think you missed the part about having to power the old scroll saw yourself, like one of those old treadle sewing machines.
Personally, I can't imagine being able to do it. Keeping a foot working for power while paying attention to keeping the blade following the line (plenty hard enough when I have electricity to do the work of making the blade go up and down) is probably more than I could ever coordinate. I can only offer my upmost respect to those who have mastered scrolling with that sort of equipment.