I have seen all sorts of things corroded together. It's amazing what happens to a 1975 schwinn varsity when you store it in the rain. My thought is with some Phill grease that is occasionally renewed, they would last a long time.
I found some 10mm od, 8mm id brass tube
https://www.amazon.com/uxcell-Length...s%2C106&sr=8-3
Maybe that's the way to go if you have a lathe or are very patient with a saw and file. They aren't lubed, but neither are the Rene Herse bushings. It is mildly entertaining what happens when you cut in to the oil-embedded brass, an amazing amount of oil comes out. I just had to do that for a project.
I can have brass washers cut, but at some point it gets tough to compete with Jan Heine. Thinnest brass I can use is 1mm, is that too thick?