I've recently added a page to the Chip Links section of my web site that lists all of the $1 U.S. Casino Chip insert variation. If you're unfamiliar with insert variations, they occur naturally, just like the SCV and LCV mold variations or small $ and large $ mold variations. In order for an insert variation to be possible, the chip must have 2 different inlays and asymmetric inserts. Very few chips meet these 2 requirements and fewer still actually produce insert variation. Here's an example (I'm only showing 1 side of the chip, but notice that the insert colors run tan-brown around the first chip and brown-tan around the second chip (you read the colors clockwise)):

I've divided my listing into 3 section:
Insert Variation (21 chips) - These chips are known to exist (at least to me).
Likely Insert Variations (19 chips) - An insert variation "should" exist for these chips, but I've not (yet) seen one.
Unlikely Insert Variations (14 chips) - Either due to today's manufacturing process or some other reason, these insert variations will probably never be found.

Many of these insert variations are listed in the Chip Guide, but some are not. If you know of any other $1 U.S. Casino Chip insert variations please let me know and I'll update the guide. Feedback is always appreciated. Thanks and enjoy!

Quick Link to Insert Variations: http://casinochips.elementfx.com/tradelist/insertvariations.htm