The stitch cams for the 158.XXXX machines pretty much fit them all - however I've read that the early machines may not have the second lever, so they will not do the stretch (double row) stitches. I think Kenmore refers to it as the "verigator"
For the monogrammer, there is a different style for the open arm machines (and maybe others too), if the monogrammer is in the box WITH the cams, it is not the same as the one that comes with the cams seperate.
Here are both - the left is what fits on the flat bed 158.XXXX series - just have to make sure the needle plate has the notch, and the plate opens towards you (not to the front of the machine). The first one has a separate box with only the cams.
Notice the difference in width and design of where it buts up with the needle plate.
The back side
And these cams DO NOT FIT the other style monogrammer (that comes branded for Singer, Greist and Kenmore).
I figured most of this out by buying and seeing if it would fit.
BTW - the button holers come with the same difference - so make sure you get the one that fits your kenmore.