good work! There is often some negative commentary on knives made from old files. I personally love that steel (at least, 90% of the steel from old files, or worn out new files if they are Simmonds of Nicholsons). I originally thought that converting files into knives was not very common, historically. However, in Person's American Knives: The First History and Collector's Guide, he points out a significant number of knives made from worn out files. So, it was done a great deal in the US between the 1700's and 1970's or so. It is only in this era of cheap mail-order steel bar stock that we don't see as many files used.
anyway, just my own take on things. I like recycling, and I use and wear out a lot of files because I file heat treated sword blades with them. So, I make my shop tools from old files, and I also make a couple of knives from old files each year.
take care,
kc