If it's a MK II, it will be marked as such.
Primarily in the magazines; Mark II has a bolt hol open also
Which one?...The Mark 1's and Mark 2's are pretty valuable...
Contact ruger and request a owner's manual
50-250
Ruger's site is not working for me. They have extensive sn data.
50-500 usd
100-450
100-550 or so
100-500 usd
$100-$350, depending on the exact version and condition. Serial number does not tell us that.
Go to the Ruger website, look under customer service, historical data
100-500 USD or so