Welcome to the Forum. I'm afraid that I cannot be of much help. Our S&W "Bible" (Standard Catalog of Smith and Wesson, 4th Ed.) gets a little sketchy with triple-alpha serial numbers like your "DNB64xx". I did a little research...the Model 327 was introduced in 2004, and S&W only made Performance Center models until 2008. Both PC and Airlite models were manufactured after that. There are some s/n's listed for 2008 that are close (DAK, DBN, DCU, etc.), but nothing in the DNB range. The SCSW was written in 2015 and published in 2016, so their s/n listing ends in 2015 with CZX. Your 327, which is still in production (current MSRP $1519) was manufactured post-2015, and likely in 2020-2022. I found some for sale on Gunbroker, "DDS" dated 4/28/2017, and a "DYV" dated 8/14/2023. Most of these have asking prices of $1500 to $2K+. Do you have access to the original PC box for this revolver? If so, its production code and manufacture date should be on the end label. Hopefully a few more Forum members will be along soon that can help nail down the manufacture date of your 327PC. It's definitely a nice revolver...enjoy!