I just picked a third c&s variety of BPOE 235 (thanx Riverboat Rick).

I think the some of the differences between chips made by USPC and the Burt company are quite evident in the scan.

The chip on the left was made by USPC. The other two are Burt chips. First note the size of the inlays. The inlay of the USPC chip is 1 1/16". The diameter of the Burt chips is 31/32". There are exceptions but generally, the USPC inlays are 3/32" larger than Burt inlays.

Second, note the color of the inlays. All three inlays started off white. The USPC chips naturally yellow due to the type of material used. USPC used cellulose nitrate while Burt used Plastic.

Other differences such as color are more subtle.

Although I consider Jim Blanchard a good friend, I hope he's not upset when I say that Burt was never able to match the quality of chip produced by the US Playing Card Co.