Those are thin knife scales that double the thickness at the grip to improve grip, especially when using a heavily textured bed for printing. There is a sacrificial layer at the holes modelled in so no supports are necessary but the layer needs to be removed after printing. The three screws are not only aesthetic but also insure that the scales are flat on the steel.
Hardware:
I recommend PETG for better temperature resistance than PLA and better chemical resistance then ABS/ASA. Print grip side down on a textured sheet.
The author marked this model as their own original creation.