@primoz, thanks for trying to find a solution. it looks impossible with the current code. Not to worry. Will work around it.
@yosu, thanks for your suggestion. Indeed I could do the transparent box behind icon thing but I was hoping to remain with the widget on this one. Editing my images will be easier for now but thanks for sharing the idea.
@toeknee, indeed you are right. I should have said transparent space around the icon. I used this method to increase the icon’s width/height to where I want it to be and solved the problem for now.
All, please take note of my remark about the use of display.newImage in the widget.newButton. This will mean your hi-res icon files will not be used if you are not supplying a width and height in widget constructor. Beware!