I just don't know.

The type font on the chip was used by several other clubs in California (see pic below: PlayHouse card room San Diego) so it's not impossible that it would have been from a California Card room, and just never attributed to the Niles Point Cardroom as of yet. That would take some work.

Made as a sample? Not impossible, but not too likely.

It may just have to be a UFC until the right person comes along who knows for sure, or can do the detective work. Or you spend spare time going through the MOGH ChipGuide doing a lot of searches for places with the ET initials. Doing a few of those every night that you have some "time wasting" time available might be good anyway. You could learn a lot of random info on chips that way, even if you never find this beast.