Below is a scan of the reverse side of the $5 "crows" chip I have. On this side you can see the remnants of the edge spots. I took a close look at the edge of the chip, and the spots do appear to me tape.

As for the $25, it appears there may be other variations out there. The $25 I have has the same markings as Christopher's chip does. Here are other scans from the film: