I bought a small, thin tungsten bar from Cleveland tools at Oshkosh. I believe it was a sort of "seconds" item. If you have problems finding something, send me a message. You could also probably make a similar one out of 1/4" steel. They are 3/32" rivets, so it doesn't have to be all that much. Yes, I like Tungsten better too, but sometimes you have to improvise. In that area, you can probably make it plenty long length wise to get some weight / mass. There's a least one or two rivets where it's advantageous to have an angle on it.