Float Pilot your sites look good. It makes me want a Ruger so I can do the same thing.
Williams gunsights will install their sights on your gun. They have a price sheet on their site.
The NECG offers a banded front sight for rugers. It looks like the factory site. It most likely is. They can be bought from Brownells.
RFC = www. rimfirecentral.com
OE I think is supposed to be OEM. I think that stands for original engine manufactuer. Don't quote me though.
I don't understand why gunmakers won't offer open sights as an option. I do not like to buy a rifle if it doesn't have open sights. Thats what I like about a Marlin lever action. Just buy the gun, go to the range, wipe out the barrel load it up and start shooting. No scopes, no bases, no bore sighting or other BS.