I no longer have a plug in light. Got rid of it when I gave up with stamps. The handheld needs new batteries I think but good enough to show.

I agree with your comments. Adding the BJ probably some requirement. 3rd chip could be further security, BJ using a different compound, or an experiment. Some such varieties are listed in TCR, others are not. I will put them on my website in case someone decides they want them after they are no longer available