The problem with scaling parts is all the bolt holes will get bigger as well. As the bolt holes get looser the bearings will start to move unpredictably due to sloppy bolt fit.
25mm stainless rail is pretty easy to find usually. If you can't find it at your hardware store as curtain rod or shower rod. Boat companies can usually get it and I can get it online though ebay, and online metal suppliers. This would be a much better choice that scaling.