I acquired some (both the Indian head and locomotive) too. (In fact these might be from my set). I call them crest and seal chips because they meet my three-part definition -- clay composition chip, litho inlay (that is, not a plain one-color die cut inlay) and flat mold (i.e., no embossed rim mold). They are not antiques, just nice, modern poker chips. Made by Atlantic Standard Molding of Maine -- round white inlay with black ink design, done by computer, I think.
Robert