If you are going to chrome plate a stock valve cover. I would do that to the earlier versions. The ones that have a scripted Chevrolet. I think those look cool, never liked the look of the stock plane looking valve covers. I used one for a while The one I have is from a 1962 or 63 Nova 194 L6 cover.
Chrome just plane leaks, not saying it is impossible to not leak, just an inherent trait, it also retains heat in the engine.
IIRC, the plain colored spring is stock, I would definitely get a kit that allows you to make adjustments for the secondary's
