Help with CS:S knife file

I accidentally overwrote the CS:S knife file in Garry’s Mod and know it is a different weapon and I want to change it back. Any help would be greatly appreciated. Thanks

delete the materials and models files?

I’m not sure what file to delete. The problem is that the file of the hands holding the knife has been replaced. I’m not sure where that is and the file names are not to obvious.

Anyone else have an idea?