Revolver
1968 - 1988.
Model numbers 117 vs 207 and external physical features
In stainless, and in New in Box (NIB) a Ruger Speed-Six in 9x19 is worth $1,000+ as of 2010. In stainless, and in like-new condition, a Ruger Speed-Six in 9x19 is worth $700+ as of 2010. The 9x19 version of the Speed-Six is quite rare in the U.S. since only a few were sold in the US from European and Israeli military/security contract overruns.
Yes
The Ruger web site has sn data if you can get to it.
75-260 or so
50-500 USD depending on specifics
100-300 USD
100-400 USD
Ruger's website has extensive sn data available for all. 150 USD or so
100-300 USD
200 or so