Try styrene strips painted with a spray aluminum paint. Of course, later this winter, you’ll have the added task of weathering them with a bit of rust…? If you have some clear, flat, plastic packaging (rolling stock, scenic materials,…?) you could cut it to size and shape, and then paint those pieces…maybe prime them first to ensure good adhesion of the aluminum paint.
I have used aluminum foil and treated it with vinegar to “age” it. I used it many years ago for the roof of a larger scaled barn I helped my brother with. At that time I thought it looked OK but I haven’t tried it yet on my N scale layout.
I have never been to Sweden so I don’t know how common aluminum foil for cooking is or if it is called by a different name. The vintager I used was standard (here in the USA) white 5% acidic vintager used for cooking.
Along with bukwrm’s suggestion, I read recently that someone on the forum would take the aluminum foil and wrap it around a large bolt (imperial or metric, doesn’t matter) to make the corrugated grooves. I thought that was a rather clever idea.
Instead of wrapping the foil around a bolt, roll a threaded bolt/ rod over the foil. Just need to find a proper backer for rolling, ie: cardboard, foam etc., this way the foil is flat for better control and trimming. I have even heard of dragging a comb over the foil.
Bob K.
The acid in the vinegar oxidizes the surface of the aluminum, changing the bright shiny new looking metal to something that looks like it had been out in the weather for a time.