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.
That is not the serial number. The sn is located on the butt of the gun.
300-450 USD
You need to get it lettered by S&W. What you list is a non-standard barrel length. If factory, seek professional appraisal.
400 or so
500-600 USD
Your smith and Wesson model 686 is valued at 250-425 dollars depending on condition.
Your Smith and Wesson model 19-3 which dates to the year 1975 will bring between 300-550 dollars depending on overall condition of the revolver,to include the amount of original blueing remaining on the barrel frame and cylinder,and the grips condition,and the barrel condition.
300 or so
100-600 usd
Depends on exact model, barrel, and condition. Around $200,
Anywhere from $250- $500, depending on condition, barrel length, and documentation (EARLY pre-war "registered" magnums with factory documentation can be worth much more. )
Wesson Fire Arms did. Values can range from 500-10000 USD dependig on EXACTLY what you have and how it is marked along with condition.