Definition of a Saturday night special is basically a low end poorly made gun,Smith and Wesson's are not poorly made,they are the best.I'm sure he was just referring to some kind of snub nose .38 made by S&W,and even in not great condition that's a good deal no matter the model if the cylinder locks up tight and it all checks out in shootable condition.
This was my thinking when I read the OP.
The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants. Thomas Jefferson
Thats no "Saturday night special ". It is a beautiful, reliable work of art, and will serve you well. Looks like a model 36 cheifs special, was, and still is, popular as a backup gun for law enforcement, can be found as an off duty weapon, and for concealed carry for many individuals (legal and criminal alike), though not as popular as it used to be.