Instructions
Check the logo on the bottom against the lists published by high-volume collectors and dealers. Note that not all authentic Fire-King was legibly marked, as the fine lines of the molds filled with debris with use, and at various times the company used paper labels.
Compare your piece to those pictured in original catalogs. Philip Hopper of San Antonio, Texas, has assembled his collection of some 12,000 pieces of various Anchor Hocking manufactures into a private museum and published a compilation of catalogs, advertising and sales materials for collectors' reference.
Compare your piece to known reproductions. Collector networks such as Fire-King.net publish information and photos, and there are collector clubs devoted to sharing Fire-King information, at least in Iowa and Colorado.