hi all, just got the para 15 minutes ago . been reading alot on this knife and decided to try one out.asked the people at new graham to please check for vertical blade play as i read it exists in some.well it has approx. 1 mm.up and down. nothing side to side.lock holds rock solid with no slipping at all.also on the thumb ridges there is black and gold staining that looks like burned metal.any ideas what that is?? is the vertical play anything to worry about because it is only going to be a working edc and certainly not a safe dweller.thanks in advance, high.