Durifort Was made by Ateliers De la Rive and was the predecessor to Vitus 172 which was a seamed double butted cromo steel, Durifort was a seamed double butted hi carbon steel, it was pretty heavy 1.1 x.9 if I recall correctly. I built about 10 frames with it when I first started building back in the early 70's. I still have a couple of Durifort decals. I got the sets from Vic Frasie of Paris Sport Cycles of N.J.
God Bless Anthony Mezzatesta Mezzatesta Custom Cycles 914 Berkley Manor Dr. Cranberry Twp. PA 16066 724-778-8224 Cell: 917-214-9229