It's our pleasure to help out and share some knowledge with the Glocktalk community! That 3" model 36 actually belongs to the brother of one of our employees, I thought it would make for a good picture after we plated it
NP3 works great on aluminum and stainless, and the S&W AirWeight J frames in particular really benefit from the protection & lubricity it provides. Metal being prepared for NP3 will get a sand and/or bead blast depending on the material, and NP3 always comes out the same dark silver satin appearance.
If you want to send one in soon we are running a special for the month of June on NP3, NP3 PLUS & Roguard refinishing - details are on our web site: http://www.robarguns.com/specials.htm