Very nice bunch of six-shooters!
I'm going to stick my neck out here but I use Gun Juice for light cleaning and metal protection. I have no schedule but occasionally re-apply. The effect is cumulative and improves the look & feel without being oily. They also make an oil pen and light grease that I lube with.
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector