If you polish the part very well and degrease it, next wrap it in newspaper dont touch it without gloved hands and visit your local gunsmith to have him hot blue it. Probably not cost much at all, just find out what days he hot blues and visit him and learn the process, I do it in my backyard but its not something if you consider to do yourself that you do inside.
PS THe trick to the pearl look you want is polishing or bead blasting with very fine glass beads, the way the part is prepared determines how the black blueing appears. IE GLossy polished part= glossy black coating, Bead blasted with fine glass beads (ALmost polished)= almost polished black coating.
Sand blasted finish (Matte look)= matte black. Many times I also use scotchbrite sanding disks for a brushed look to my blueing.
Goodluck
Chris