DIY: What to do with those old coins from other countries.

I was inspired by "What I Wore blogger", Jessica Quirk. http://whatiwore.tumblr.com/post/20791295255/diy-charm-bracelet

I made my own coin bracelet

I added more coins than she did because I had a heavy chain to use so it would support more weight. I had my husband drill the wholes with his drill press. This was much easier than trying to do it with a hand held drill. My fingers aren't strong enough to keep the coins spinning while I was trying to drill. I used regular jump rings as well I didn't want to fuss with the double jump rings too hard to put on.  I did clean them in a sonic jeweler machine to get the dirt off. Have you ever made a coin bracelet? My question is should I polish the coins or leave the brass and copper patina old as it is?