Keep the oil passages clear. Those flecks of hard plating from the cylinder combustion chamber cuts, are just the sort of hard nasties, that like to sneak under the saddle and scar the ways so easily.
They''ll slowly leave marks, that resemble piston scoring, on the ways. if not kept cleared out.
Need a bit of oil in the holes ,each time, to help flush them out somewhat.
oil it, roll it back and forth a couple times and wipe off that metal flake looking swarf that shows up from underneath the saddle on the ways.
repeat the oil and wipe a "couple" times till oil looks clean from under the saddle.
rusty stuff is harsh too (much like lapping compound) do a same/similar method with the oil as above till clean oil shows.