Any ideas where I can get brake pipes that more closely resemble the original style I.e. a bit thicker than newer type
I see Back to Classics in Holland do rubber hoses & the metal tubes for the front brakes on the Darmah so suspect they do them for all the models. See https://www.ducaticlassics.com/parts/900-sd-and-ssd-darmah/all/front-brake-system
