Where to find the installer for SQL Server Native Client 11.0.5058?
SQL Server version 11.00.5058 is SQL 2012 SP2, so you need to download Microsoft SQL Server 2012 SP2 Feature Pack

There are several places where you can look up the exact version of a build number. Personally I use sqlserverbuilds but there are others.

Once you find the name of the build you can use that to google and it may lead you to the correct version of the installer or feature pack you need.

If you click download on that page it takes you to a list of packages you can select that looks like this: