I tested these with my eyes, ears, a $5000 LCR, a spectrum analyzer, and a hammer. I also tested the real thing (NOS pre 1960 Sprague, post 1960 Sprague) and compared notes. The old ones had drifted to as much as +40% C, and the Q was all over the place. They were not as bad as the used "pulls" we tested. Used caps ("PULLS") suck! These are close enough for me to say "If you want the look and tone buy it". I would spend the extra money over buying old caps. All used caps have a high rejection rating when tested. The Allparts caps are consistent. They are within spec. Are they a real clone? Without a time machine I can't say they are 100% the same. Caps age. How they age depends on how they were used, as well as how they were stored. Unused NOS caps from Florida will differ from caps stored in Arizona. The insides looked about the same as the real deal. (paper, foil, stinky oil, in a plastic casing) The new ones were tougher to smash open.