Shim to prevent J-head on Wade Extruder from rocking

I have a homemade Prusa I3 rework style printer with a Wade type extruder and an E3D-V6 head and during extract moves the head moves slightly up and down and that cause it to shift slightly.
This shim is slide in place at the base of the extruder where it connects to the head and prevents this action from occurring. I've heard others that this problem, so I'm making it available.
If it doesn't fit, you may have to sand away some material or edit the .SCAD file as needed.

Narrow slot goe