Well?.
I know that what I know is only what I think I know, and since that is what I think, I am cautious about going out on a limb with information that might be misconstrued as knowledge.
But since you asked, I have seen a couple sets of 5-sided chrome fenders in my time. When the first set turned up on a pieced together CWC bike, local opinion was that they were some sort of aftermarket replacement fender. Later a reference was found in Huffman-Dayton literature that depicts optional ?Colonial? pattern fenders with a distinct 5-sided cross-section. I think the reference may have been in a 1937 catalog but I don?t have those references handy to me now. If someone else doesn?t come up with the illustration I?ll try to dig it up.
I haven?t seen an unimpeachable original Huffman-Dayton with Colonial fenders to compare to or measure but Scott?s fenders look just like the other 5-sided fenders I have seen. A test would be to see how the mounting holes line up to a frame.
Phil