So if you carried a fairly large ball bearing in your pocket, that would be a deadly weapon. If you carried a good sized rock in your pocket, that would be a deadly weapon. If you carried a tightly rolled up newspaper in your back pocket, that would be a deadly weapon. Would the passing of some rather odiferous gas be construed as being "deadly"
Point is, darn near anything is capable of inflicting death and could be adapted for use as a weapon and carried for that purpose by someone..
Weapon laws are stupid, They are created by morons. There should be no Weapon laws of any kind. You should be allowed to carry whatever you want to carry. When you use it to injure or kill someone unlawfully (murder). Then you should be dealt with harshly by the law. If you injure or kill someone lawfully, (self defense), then you should not be in jeopardy.
So it shall be written, so it shall be done...