As usual, I searched the internet for a file handle but didn't find any that looked right, felt comfortable or fitted the file, so I designed my own in DesignSpark.
I printed this in PLA adding an extra perimeter and increasing fill density.
If you want this for a smaller or bigger file you can scale the stl or modify the design with the enclosed RSDOC file using RS DesignSpark Mechanical.
The author marked this model as their own original creation.