Jim, as far as those Jack Niemann chips....
The 50¢ chip is an example of a low-priced line I didn't discuss in this thread. They are simple, solid-color chips with a suits-type mold and usually hot-stamped for roulette use or as a low denom chip, as here.
Moving up in price from the hot stamps, there is a "24-groove" line of roulette chips (that used to be called R4). It's a plain mold with grooves emanating from the center to the edge, usually with 12 very small white edge "spots" molded in. There is a nice printed inlay, often just a simple stock drawing, though many casinos get them custom-printed as roulette chips and a letter designating which table. These are made from a composite material that's like the S2 chips, but maybe a little softer feel. These play and shuffle great!
But the $1, $5 and $25 Niemann chips are not the same as those roulette chips. I have a chip like those, and they are a strange combination.
First, the mold design is definitely from the options available only as S2-type molds -- that's the key feature. Next, the size of the inlay and the 4-color printing are also S2 features. My chip is very light (8.25 g), lighter than the unslugged S2s but al ittle more than the weight of the roulettes. But the distinctive 24 grooves in the mold make this a hybrid chip IMO. I don't know if it was an early model for the S2 chips and they used the 24-groove mold for a time, but I don't think these are made this way any more.
So I would call them S2-type chips. But I'll see if I can find out anything else.
