LAQUITA

I recently bought this set up from a lady, and after getting it set up, I noticed that it has possibly 2 different kinds of stitch regulators on it. Let me explain.

bottom Picture shows the dial on the handle bars. As I turn this it either increases the speed of the machine and stitch length or slows it down and adjusts the stitch length accordingly. It Is plugged into the top picture which is the older Grace model sure stitch. I Do not have any other pieces to the Grace SS. There is nothing else that came with it, I've talked to the lady I bought it from & she says that this was all she'd ever used.

I've never had one of theses but as I look them up on line, it appears I have 2 partial units, however I can't find anything on the one mounted on the handle bars. Sewing with it, it seems yo work as I'm told it should worh the stitch regulator.....but I'm confused as the 2 different parts, and yet it seems to work. Can anyone please help ...un confuse ���� me?
Thanks everyone.