None that I am aware of. They were standard production is appeared in the 2007 Catalog. The kits were sold prior to that as evidenced by box date codes I have found, as early as 2006 and as late as 2008.
While I did say in the previous thread I did note not a deference between SKUs 150125 and SKU 150152, there is difference in the front sight. SKU 150125 has a green hi-viz and SKU 150152 is a red ramp, same configuration as the Kit ES.
Thanks Ruggy. Mine is an early version, test shell casing dated August 2006...I also called S&W and confirmed same. Thanks again for the info and link to thread.