Must be examined by a good gunsmith to determine if safe for modern loads. Value depends on condition and specifcs that you don't mention.
1965 if it is an auto-5. There should be markings on barrel to indicate choke.
$317
Serial number 332055
It is worth what ever the market will bear.
100-360 USD or so
50 USD
32 inches would be the longest to be listed as a "standard" length. Anything longer would be considered unusual.
how old is my Iver Johnson single barrel shotgun champion model 3578 C with a 12 gauge choke bore barrel and lug forged in one and approximate value .
The barrel length you give is not a standard one. You need to contact S&W to verify that it left the factory with that length barrel. It will affect value.
Blue Book of Gun Values will help.
Barrel is 21.5 inches long. The attached link is an article on them, with photos. Using a barrel length of 21.5, you should be able to scale the approximate overall length from the photos.
50-100 USD or so