Finally, something I know a little (
very little) about!

You have been told now that the base plates are all brass or nickel plated aluminum or brass Maz. The "almost impossible" comes from the nature of stainless steel. The corrosion resistence that makes it so appealing is due to the chromium content. That same chrome content makes stainless feather or tear when machined.
The particles from a machining process with normal carbon steel has residue as well but most falls away or can be blown/vacuumed away during the machining process. Stainless on the other hand is almost like glue as far as particles sticking to each other and the piece being machined.
That's why in the manufacture of stainless items such as weapons or any other component that has stainless contacting other stainless, different grades of it are used to prevent the galling or seizing effect. The greater the heat generated from the friction of the process or post machining, in normal use, the greater the tendency to stick to itself. Example would be a 400 series stainless for a pistol. 410 slide with a 440 frame is dissimilar enough to drastically reduce the tendency to stick to itself although the heat from the 2 pieces sliding against each other is considerable.
That cannot be avoided in machining and as particles build up from the heat of the machining process, it affects both the stainless itself and the equipment being used to work with it. Depending on the complexity of the design being machined, whether by hand or these days by CNC milling machines, this buildup of stainless can and does make many small precision pieces almost cost prohibitive to make (unless you're a government or government supported manufacturer

).