I know I'm probably preaching to the choir, mostly, but here's my rant. If you build new amps, don't use up the vintage correct Mustard caps, Iskra and Piher resistors, and other parts that are no longer being made and are in short supply! It's a new build, use new parts. SoZo caps are as good as vintage Mustard caps ever were, and you can't get better resistors than Dale/Vishay metal film or metal oxide resistors. Today parts quality is superb, and WELL above the level of parts quality in 1970. The only reason to use NOS vintage correct parts in a new build is to butter up your ego. They DON'T increase the value of your amp OR make it sound better. But every one you use is one more that can't be used for a restoration. Leave those parts to those of us who restore those amps to their original state, as much as is possible. They're scarce enough already. Besides...don't limit your amp's performance by installing parts made half a century ago. Modern parts can be BETTER. More reliable, 50 years newer and thus not suffering from any age effects, and quite possible, if you pick the right ones, they'll have the same sonic qualities we value in the vintage parts, or even better. I posted this in response to having been browsing the internet this morning and encountered an ad from some yahoo who wants to seel his new built Marshall clone and it's chock full of NOS parts. What a waste!