Murph; The chip you are showing was issued back in 1996 when the present Tropicana property was operating under the old TropWorld name ... when gaming regulations probably did not specifically call for "Atantic City" to be on the chips back in 1996. NONE of the chips in the entire TropWorld series, from the $1 to the $5000 denomination, have the words "Atlantic City" on the chips.... except for the $500 denomination in which "Atlantic City" is on the Lifeboat. It wasn't until the Halloween, 1996 chip that "Atlantic City" began appearing on Tropicana chips. My assumption is that gaming did not require it back then... but does now.

Also, you might be interested in knowing that the variation of the chip you are showing in your post(TWD-25)does not have the security micro-dot on the numeral "2" of the reverse side. There is a second issue of that identical chip which DOES have the security micro-dot clearly visible on the numeral "2" (TWD-25b).

Sounds like you might be in need of a copy of "Black's Catalog of Atlantic City Chips & Tokens" for your reference library.