Welcome aboard from ol' Wyo.
Thank you for sharing your "charactered" Chiefs Special with us.
Based on a few others in the database and the ampersand in the
Smith & Wesson text on the left side of the barrel, I would say the
company likely shipped yours in 1974.
Yours is a perfect candidate for a soft cotton cloth, a tube of Flitz
Polish, some time, and a wee bit of patience. I believe you would
be amazed at the results. They might even prove worthy of a set
of replacement magna stocks with the checkering still intact.