Nice looking knife
Always lots of character in old files and rasps
I've made lots of file knives and since I only use a couple of brands of file I took the time to try some heat treating recipes to make sure they worked. That then led to me just retempering the file instead of going through the extra steps of normalising and hardening
I do all of my grinding post heat treat anyway so keeping it cool was no trouble for me and the tang area can be drawn off to soft easily with a torch for drilling/filing (filing a file always gives me a strange sense of gratification).
The next step is to make other tools from files, of course being able to forge is helpful there. I've got a number of turning tools above my lathe, centre punches, chisels and scrapers made from files because they are handy bits of hardened steel that can be modified into a tool mid job (though I often have to draw the tempers back with a torch to make them safer/better)