Invention is always Good! I made one similar to yours a few yrs ago,I used 3 sawzall blades & a nail plate bent in 1/2 lengthwise,of which houses the blades & makes the handle,about 6" long closed.I love the idea of yours with the corona sharpener,Very multi-purpose Indeed!The corona sharpener also serves to be the Best striker, for ferro rods too!2 thumbs up for you!