Well bikercat, old files would work just great for that. I sometimes give a round flint steel I buy from USA Knifemaker with my knives. Like right now I'm making a pair of hunting knives for a man who wants to give them to his son for Christmas and the handles are made from his son's first Mule Deer's antlers. A 4" drop point skinner and a slim 3 1/2" bird and trout knife.
I cut off one of the antler's points for a handle for the flint steel. I just finished the sheaths for the knives and am now making a small belt sheath for the striker and added a small diamond hone for sharpening in the field. Now the man wants me to make a matching belt to go along with the sheaths, ok you're paying for it. lol
Here's a link to a video on how to make a striker flint from an old Nicholson file. By the way, the file doesn't have to be a Nicholson just a decent old worn out file. You can use a new file and have a double duty survival tool if you want.
https://www.youtube.com/watch?v=nBrX2gi80Ts&t=635s