Ruger's web site has sn tables.
Go to Ruger's website. They have a sn look up section.
You can request a owner's manual at the Ruger website.
You can get a manual for free by going to Ruger's web site and requesting it.
You can contact Ruger Customer Service through their website, and/or post a question here.
50-175 USD
Which one?...The Mark 1's and Mark 2's are pretty valuable...
$350-$500, depending on the exact version, and the condition. The rifle is a Number 1, not Mark 1. Only Ruger pistols are Marks.
Made in 1975.
50-250 USD or so
Primarily in the magazines; Mark II has a bolt hol open also
The Ruger Mark I was produced from 1950 to 1981, and serial number 15095 suggests it was manufactured in the early 1950s. Specifically, based on Ruger's serial number records, this firearm is likely from 1952. For a definitive year, it's best to consult Ruger’s factory records or a detailed reference guide on Ruger firearms.
If you are seeking date of manufacture, contact Ruger through their website. Values depend on condition- anywhere from $100-300.