Change properties of newButton() after it's created?

After I’ve created an object with newButton(), is there a way I can change the defaultFile? Here’s how I set it up.

      function() 
        logo = widget.newButton({
          defaultFile = 'customlogo.png',
          width = 420, height = 200,
          x = display.contentWidth * 0.5,
          y = display.contentHeight * 0.5 - 250,
        }) 

It doesn’t seem to be possible at the moment through the API, and I didn’t find a property for the visual rectangle in the button object, though did find a way to change the ‘over’ image.

You would have to resolve to either, making a second button to replace the current, or making your own button module which shouldn’t be much for just making a rectangle/image with a text label and touch listener.

Here’s the widget code for reference: