I have a cheap folding knife, slip joint with wooden scales. I bought it as a souvenir in France a few years ago. I thought that as it didn't lock it would be legal carry, but as it was about 8.5cms blade length, when I got home, I found I couldn't carry it legally without a reason. Hence the mod! I broke off the tip last year, and today I reprofiled it to make it legal carry.
Joel