I Googled "guardian angel". It turned up McGrath's first one and some others. Here's a few from that search:

http://www.puzzlehistory.com/grdagl3.jpg

http://www.christcenteredmall.com/stores/art/hahlbohm/guardian-angel-zoom.jpg

http://www.skeptiseum.org/images/guardian_angel.jpg

http://www.vansciverbobbinlace.com/Guardian%20Angel.jpeg

http://members.shaw.ca/zidonja/guardian%20angel%20water%20colour%2022x28.jpg