Engraving, anodizing, or phosphate coating a raw aluminum lower

[patientpatriot]

Does anybody out there know of anyone who does standard engraving(non-laser) and either anodizing or phosphate coating on raw aluminum lower receivers? I will eventually paint the whole weapon with duracoat or cerakote, but would like to have something on there in the meantime while function testing, plus having black under the final finish would be better in the event it gets scratched.