The old design comes in at least three varieties differing in the small number at the top. I have 0194, 1097, and 0699. I've always assumed these are the date of manufacture, so there may be more. Can't read the numbers on your scan... are they the same?

I also agree there are different size numerals on the denominations on these varieties. My 1097 has the smaller font.

My new design chip has numbers 0601.

Since these chips are used at casinos in different locations, the dates may indicate a new order as a casino in a new town opened.

DonL