ZT 0551, Hole in frame lock? Any expert Help available?

[smcjoecohen@yahoo]

I got my Zt 0551. Nice Knife, good looking, very strong detent. What I'm curious about is the fact that my knife (serial # 1505) does not have the little hole near the corner of the framelock. I've seen videos that explained the 0551 has that hole and 0550 didn't. It does have a circle cut in the upper left corner of the Frame lock, which is part of the framelock separation, but no hole. Someone suggeted that the blade might have been switched on my knife, but that seems ridiculous to me. Why bother. Anyway it's a curiosity.

 

[kreole]

edit: nevermind misunderstood

 

[ceptor781]

Some lock bars have blind detent balls and some don't. Sounds like yours is blind. Nothing to worry about.