First, get other opinions before you do anything. Structurally you might be ok the way it is because your string angle will actually be greater than the angle that your groove shows, so your string will be pulling more downward on the tip I think. Still, there's not much meat above your string groove.
I personally would make the string groove the new tip of your bow by removing that horn of wood above the groove and cutting a new groove down lower. But you don't have alot of overlay to play with so I might grind that one off and start anew. In fact, I know I would put another on there. But I don't want to sway you into going into something that may cause you to ruin your bow. Because the tips are pretty thin up there now and you have to be careful about working there.
It depends on you.
Definately don't attempt something at this stage that you are not sure of.
If its ok with you I'll post pics of my tips that i just did, on this thread tomorrow, and talk about it some more.?