Cleanest Factory 115grain 9mm Ammo

[envino]

Hey guys, I've taken a couple photos of my Luger's trigger sideplate as an example of some spotting I notice on various areas of the sidearm.

I've attached two photos of the sideplate: one standard and one macro of the upper right corner of the sideplate.

Is this active rust? If so, how should I address the rust correctly: using the 0000 steel wool and what other measures?

How will I know when I've sufficiently removed the rust?

Thanks for any insight!

Jeff