Just finished a chat session with S&W to confirm my date of manufacture. I asked about the spring and was told they don't offer that part for retail sale. Blah, blah, blah. Said the usual bs; see if Numrich, Midway, Brownells. That's insane. Going the same way Colt has with parts. Watching a video earlier it doesn't look all that different from a 1911 thumb safety / slide stop plunger spring. Probably is. Hope someone specs out the spring for us.