have the slots widened. However, you could probably
grind the bar down at home....and it WOULD be cheaper.
I would strongly recommend, though, that you take half
the difference off each side, to ensure that the pivot
point for the gauge will remain centered on the bar.
Regards
Dave Mundt

Why does it need to be centered on the bar? I mean, it is going to be within
a 1/8" of the center anyway? It should make no difference at all where the
pivot point is since the gauge is not pivoting when you use it anyway.

Better instead to just grind one side so you at least have one "factory"
edge to it. It will save you trouble.

-Jack