I would get a sample of each -- photos can be really misleading when it comes to these small differences. In the pics above, the top one looks golden while the bottom one looks pink, but my experience is that champagne often looks somewhere between nickel and brass, while gold looks more like a traditional brass but brushed. I'm sure that seeing them in person would help you decide! If you're doing a gold metal in a mix with nickel, I'd want to be sure that the contrast was clear.

Why not stop with all the matching you have going on and get some nice lighting in a nother finish . I am not which since I do not see your space but IMO all matchy makes for a boring space . I think DR chandeliers are a stand alone piece usually bought to be the star in the space and do not need to "go with" any other lighting.

I guess it depends on what folks hold in definition. A patina is an oxidation or chemical process on metals like brass and copper. It can over time become protective of the metal. If it goes verdigris, that can be bad for consuming. Objects can have a patina without being used, brass can develop a natural patina in a year or two of use. Depends a bit on the humidity levels in the house. It can take longer to develop a heavy or very dark patina. It is coating of the metal, not really the same as used and old. Used and old can be just used and old- scratches, finishes worn off, finishes not cleaned and allowed to darken while other areas see highlighting from touch. Patina can be worn off on a used and old finish too, like a brass doorplate gone dark while the knob stays bright since the patina is worn off all the time from use. But if you want used and old looking, or a faux patina... take the hardware off. Tumble it with some rough grit a bit. Then put them through an ammonia gas process for a while. Wax and polish after remounting to create the used/rubbed off worn areas of hardware of used and old looking. You could also try salt or acid corrosion to hasten a worn or used look, your mileage may vary depending on how you process. You could also use brass black to darken your brass to create false age. Out of curiousity, if you wanted faux aged/patina brass, why did you get raw brass?

I realize that these original door knobs that came with our house are nothing special but I was curious and took some bar keepers friend to them and they polished up pretty shiny. I don’t know much about metal finishes but is this unlacquered brass or oil rubbed bronze? The first picture is before and then after. The last picture is in between when I “kind of” polished it. Just did a kitchen renovation and am trying to decide on hardware and this might help me make my decision. Thanks!