You can get what you want by using the Customize capability in JMP.
If you generate a histogram using Graph Builder, specifying not to draw the Fences, one can then use the Customize to add back in the Fences you want.
Right click on the graph and select Customize. Then click on the + to add a script, and copy in the simple script commands into the Customize window, and press Apply. It will add in the 2 fences you want.
Jim