I have found a few large ones at flea markets and garage sales over the years.
I love using files, the feel of a nice sharp file cutting a shape or draw filing is very fulfilling to me.
Years ago I picked up a large Grob Band Filer thinking I could convert it into a bandsaw. It wasn't possible but I still have that monster in the barn.

If you like I'll look and see if I still have one of the big files out there.