I am trying to export a figure as a .EPS file using Export["Fig.eps", Fig, "EPS"].

However, the exported image looks slightly different than that in the notebook. Specifically, the custom overhat I am using is no longer centered over the symbol below it. Here is the code I am using for the overhat and a simple example:

OverHat /: MakeBoxes[OverHat[a_], form_] := 
  With[{s = 0.9*First[Rasterize[a, "RasterSize"]], ab = MakeBoxes[a]},
    With[{sl = N[2 Log[2 s]]}, 
    InterpretationBox[
     OverscriptBox[ab, 
      TagBox[GraphicsBox[{Thickness[0.105], 
         LineBox[{{-s, 0}, {0, sl}, {s, 0}}]}, 
        ImageSize -> {s, Automatic}], "LongOverHat", 
       Selectable -> False], DiacriticalPositioning -> True], 
     OverHat[a]]]];

OverHat[a]
Export["fig.eps", %];
Import["fig.eps"]

I read elsewhere that the following code allows one to export images exactly as they appear in the notebook:

SetOptions[$FrontEnd, PrintingStyleEnvironment -> "Working"]
Export["fig.eps", OverHat[a], "EPS"]

However, my exported image still differs from the image in the notebook.

Is there a way to solve this problem?