AppleScript to show package contents of hidden original of alias

folder "Contents" of also works with aliases:

on run {input, parameters}
    tell application "Finder"
        repeat with f in input
            open folder "Contents" of f
        end repeat
    end tell
end run

You can also assign a shortcut for showing package contents from System Preferences:

Command-R shows the original file of an alias.

You can try something like this:

   on run {input, parameters}
    tell application "Finder"
        repeat with oneItem in input
            if kind of oneItem = "Alias" then set oneItem to oneItem's original item
            set contentsPath to (oneItem as text) & "Contents"
            if oneItem's container as text = (path to desktop as text) then
                open contentsPath
            else
                set target of window 1 to contentsPath
            end if
            activate
        end repeat
    end tell
end run

You may also want to include a test to make sure the input is the expected type.