The only place I have ever found Flitz is at the gunclub I worked at in high school. I'm not sure if all gun clubs carry it, as its a metal polish. In fact I still have the original tube (similar to toothpaste) that I purchased 6 years ago since not a large amount is necessary. If I recall the cost is relatively cheap, maybe $10 at most. Just found that they have a website, that is cheap looking but hopefully will give you some better information http://www.flitz.com/
Good luck!
Adam
P.S. If it comes to where you can't find it, I can buy some of it and send it out to you guys but I really dont think that its that rare.