Here's mine from a fiat coupe 16vt:

Not quite as light as the others with the full dish effect but my engineer who does the engine tuning for the Integrale's said that by losing too much weight is not good for the engine as it will lose rotational mass, he said this is the best for a track day engine, unless you are only ever going to drive on flat tracks.
Also it makes a difference where the weight is taken from (the outer or the inner), with weight taken from the outer having a greater effect. There is a 4kg total difference in weight.

I combined it with balanced internals as well. Now when the engine goes on a hunting spree it fluctuates like a nutter, it also struggles to idle <~1100

So don't go too light, and also think of the safety of your passengers if it breaks!