I have a myler kimblewick and it came with little loops that unscrew in the middle to attach the curb chain. I used to to have a myler comfort snaffle with hooks - is yours like this? If so it had some very tiny holes behind the slots where the cheek pieces attach where you could add the links for the curb chain. I assume you could buy the links directly from myler or I've seen the traditional type of curb chain hooks in the robinsons catalogue. I prefer the myler ones as there's no chance of them catching on anything.
Hope this makes sense.