Well after putting the dimensions into AutoCAD it appears that they do use similar mounting positions:

(JLW/U360 is red, JLF is green)
Feck knows what went wrong with my calculations. I should have remembered that they fit any way as I CNC drilled my cocktail CPs so that my mounting bolts would accept either joystick. It was 6am when I posted so thats my excuse

If you use the dead center of the U360 plate to mark your hole centers they should line up with the inner edge of the JLF slot.