In my book, it is an error. However, at a surface level, I do not know what was the cause, and there are several to ponder...

1. Was the notch, cut into the body of the chip for the insert, smaller than usual? And if so, how was it that the insert was a full-sized insert? Perhaps, if it had been full sized, the cups would have cut off the excess, or it is a possibiity that the full sized insert was cut shorter by the operator?

2. Is it possible that both the notch and the insert were both correct at full size? While hard to image, there is a possibility that during the fusing time (which makes the chip body and inserts a very thick paste) the chip body spread over the top (on both sides) surface of the insert, except where it is closest to the edge. Again, not likely, but certainly not impossible, as we see this all the time at the rolling edge side of an insert where much of it dissapears under the spreading flow of the chip body.

In the end, the Quality Control department, I believe, would have been hard pressed to have noticed it.

Again, just my opinion and observation, and if the chip were mine, it would be with my other Error chips.

Nice find Frank!

Jim