I've been automating numbers and the one thing I am stuck on is cell borders. I've found some suggestions which appear to be for older versions of Numbers and where I am at is the following script:

Applescript:

tell application "Numbers"
   activate
   tell document 1 to tell active sheet to tell table 1
       set selection range to range "D13:AG13"
   end tell
end tell

tell application "System Events" to tell process "Numbers"
   if menu item "Show Inspector" of menu 1 of menu bar item "View" of menu bar 1 exists then
       keystroke "i" using {option down, command down} -- “Show Inspector” menu command
   end if
   tell window 1 -- inspector window
       click radio button "Cell" of radio group 1
       tell scroll area 4
           tell button 3 of list 1
               set {xPosition, yPosition} to position
               set {xSize, ySize} to size
           end tell
           click at {xPosition + (xSize div 2), yPosition + (ySize div 2)}
           
           select button 3 of list 1
           click button 3 of list 1
           
           click menu button "Border Styles"
           click menu item "1 pt" of menu 1 of menu button "Border Styles"
       end tell
   end tell
end tell

What is not working is the "select button 3 of list 1" which fails to click on the all borders selection of the 3x3 grid that selects different border types. I can see  'Border' box cell getting selected, but it doesn't change colour when clicked by AppleScript in the way that a real mouse click does.

Feels so close to what I want!