S&W build date?

[Cruisers460]

Picked up a Smith Wesson 28-2 at the gun show today. Serial #S323xxx anyone have a book to date it?
Thanks.

 

[BillsCamino]

Late 1968 – Early 1969

 

[Cruisers460]

I just noticed the parts list prices are effective March 15, 1967.