Blackberry

I know I mentioned in my last post that my last purchase simply has to be my last one. Well, it was not. I guess I simply have no will power. Here is my latest find. This was a yard sale with all proceeds to go toward the adoption of a little Russian girl. She was just so cute I just couldn't resist helping in some way. This is a Kenmore 158-17550 that runs very quiet and makes a lovely stitch. As near as I can tell it was made in the late 60's early 70's. It is all metal with a vertical bobbin. It came with a nice collection of accessories and cams but no manual and there doesn't seem to be one available on the web. I have pretty much figured out how to thread it and how to work the stitch dial and the dial that turns to cam when using the cams and turns to a couple of other zigzag stitches. However, my problem is that when I put in a cam, the machine runs in reverse and I can't figure out what the problem might be. The reverse knob works just fine when sewing a straight stitch. Also there is a little knob with a plus and minus on it on the back of the machine and I have no clue what that is for. Here are a few pictures. This machine has not had a lot of use and in fact seems to be in nearly new condition. I am hoping someone on the board can help me with the reverse stitching problem and possibly with a copy of a manual.