http://www.shapeways.com/model/310385/amiga-3000-disk-drive-eject-button.html?gid=ug96598#
Think the deal with these was that you had to glue them on the drive. You might also want to paint it a different color to match the case.
About to order some myself soon to see how they work out 
Yeah I ordered a few and hot glued one to a drive and thought it worked out pretty well. The one I received had a pretty rough texture, but certainly better than nothing!
