it's too bad s&w sn aren't readily available.
Their serial numbering system- or, more specifically prior to March 1984, their lack
of a consistent system- would foul any attempt to publish a "readily available" index. The numbers are just too mixed up.
To complicate things further, S&W often built and sold guns out of serial number order in past decades. When handgun sales tanked during the Great Depression, frames were sometimes stockpiled for up to 10 years
before being assembled into a gun and shipped.
It was during this time that S&W went into the business of making razor-blade sharpening tools ("Blade-Savers") and toilet flush valves to keep from going out of business; I'm not making this up!