I believe the rivets should be rolled and not just smashed if you are going for the original look. The tool head has a special shape. I thought this had been discussed on FB before and a photo posted but couldn't find the thread.
Here's the idea -
http://www.clevedon-fasteners.co.uk/...-rivets-5.aspx
A tool used with a hammer -
http://www.jmurrayinc1944.com/produc...ubular-rivets/