HMMM, good question. I would have to say late 1999 or the first part of 2000. They discontinued the Shadows in early 2000 and all remaining stock here in the states was liquidated from distributors.(you still may be able to buy them here and there, I can get my hands on a few certain sizes myself I think if I really dig) The factory had some up until a short time ago in stock, but I believe they were built during the same timeframe. I sold quite a few back then and noticed the shims but as stated they never affected performance at all. Good shooting, P12