Bill,

I just made a profile (using red oak) to insert in the slider of my B3.

The measurements for the piece is will use on my machine are:

21.8mm for the bottom width (32 on your drawing)
9.6mm for the thickness of the bottom wing (10.0 on your drawing, but I purposely made mine a little bit thinner)
11.0mm for the width of the groove (20mm on your drawing)

I hope this helps; let me know if you have questions.

Regards,

Jacques